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Modification of the fenvalerate-induced nociceptive response in mice by diabetes
Brain Research 948 (2002) 17–23 www.elsevier.com / locate / bres
Research report
Modification of the fenvalerate-induced nociceptive response in mice by diabetes Junzo Kamei a , *, Emiko Iguchi a , Mitsumasa Sasaki b , Ko Zushida a , Kayo Morita a , Shun-ichi Tanaka c a
Department of Pathophysiology and Therapeutics, Faculty of Pharmaceutical Sciences, Hoshi University, 4 -41, Ebara 2 -Chome, Shinagawa-ku, Tokyo 142 -8501, Japan b Basic Research Laboratory, HALD Inc., Yokohama 236 -0003, Japan c Department of Neurobiology of Aging Laboratories, The Mount Sinai School of Medicine, New York, NY 10029 -6574, USA Accepted 18 April 2002
Abstract We examined the effect of diabetes on the fenvalerate-induced nociceptive response in mice. The intrathecal (i.t.) or intraplantar (i.pl.) injection of fenvalerate, a sodium channel activator, induced a characteristic behavioral syndrome mainly consisting of reciprocal hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs in both non-diabetic and diabetic mice. However, the intensity of such fenvalerate-induced nociceptive responses was significantly greater in diabetic mice than in non-diabetic mice. Calphostin C (3 pmol, i.t.), a selective protein kinase C inhibitor, significantly inhibited intrathecal fenvalerate-induced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level those observed in non-diabetic mice. On the other hand, when non-diabetic mice were pretreated with phorbol-12, 13-dibutyrate (50 pmol, i.t.), the dose–response curve for intrathecal fenvalerate-induced nociceptive behavior was shifted leftward to the level those observed in diabetic mice. These results suggest that the sensitization of sodium channels, probably tetrodotoxin-resistant (TTX-R) sodium channels, by the long-term activation of protein kinase C may play an important role in the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice. 2002 Elsevier Science B.V. All rights reserved. Theme: Sensory systems Topic: Pain modulation: pharmacology Keywords: Diabetes; Nociception; Fenvalerate; TTX-R sodium channel; Protein kinase C
1. Introduction Most neuronal sodium channels can be blocked by tetrodotoxin (TTX), with Kd values of 1–10 nM. However, sodium channels that are resistant to the blocking action of TTX have been found in both the central and peripheral nervous systems [5,14,47]. Dorsal root ganglion neurons express a slow activating and inactivating TTXresistant (TTX-R) sodium channel as well as a fast activating and inactivating TTX-sensitive (TTX-S) sodium channel [7,24,26,29]. The TTX-R sodium channel is *Corresponding author. Tel.: 181-3-5498-5030; fax: 181-3-54985029. E-mail address: [email protected] (J. Kamei).
predominantly expressed in the capsaicin-sensitive small neurons of the dorsal root ganglion and appears to play an important role in nociceptive transmission [1,3,28,34,36,43], and especially in allodynia and hyperalgesia [33]. In spinal cord astrocytes, protein kinase C enhanced TTX-R sodium channels, with leftward shifts in the voltage-dependence of both activation and inactivation, and produced faster kinetics [44]. Pyrethroid insecticides are known to modulate the gating kinetics of neuronal sodium channels to cause repetitive discharges and membrane depolarization. In TTX-R sodium channels, fenvalerate, a type II pyrethroid, irreversibly prolongs the sodium current during depolarization and greatly augments and prolongs the tail current [40]. Recently, we found that i.t.-administered fenvalerate pro-
0006-8993 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. PII: S0006-8993( 02 )02944-X
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duced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs [20]. Such characteristic fenvalerate-induced behavior was inhibited by morphine, mexiletine (a sodium channel blocker), MK-801 (an N-methyl-D-aspartate ion-channel blocker), and GR82334 (a neurokinin-1 receptor antagonist) [20]. We also showed that calphostin C, a protein kinase C inhibitor, inhibited fenvalerate-induced behavior [20]. On the other hand, phorbol-12, 13-dibutyrate, a protein kinase C activator, markedly enhanced the fenvalerate-induced behavior [20]. Based on these results, we suggested that the intrathecal administration of fenvalerate induces a marked nociceptive response and thermal allodynia / hyperalgesia, and suggested that TTX-R sodium channels may play an important role in this effect [20]. Hirade et al. [13] recently described the functional changes in TTX-R sodium channel activity of dorsal ganglion neurons in diabetic rats. Based on an increase in current density and a leftward shift of voltage-dependence of gating states of the TTX-R sodium channels, they proposed that TTX-R sodium channel function was altered in diabetes, which explains why neurons participating in nociception are highly excitable in diabetic animals. Allgren and Levine [2] reported that both the mechanical behavioral hyperalgesia and C-fiber hyperexcitability in response to mechanical stimuli seen in streptozotocin-induced diabetic rats are reduced by agents that inhibit protein kinase C. Furthermore, we recently reported that i.t. pretreatment with a protein kinase C inhibitor, calphostin C, attenuates thermal allodynia and hyperalgesia in diabetic mice [31]. On the other hand, in non-diabetic mice, thermal hyperalgesia and allodynia were caused by i.t. pretreatment with a protein kinase C activator, phorbol12, 13-dibutyrate [31]. Moreover, we also demonstrated that i.t. pretreatment with calphostin C reduced the enhanced formalin-induced nociceptive responses in diabetic mice to the level observed in non-diabetic mice [32]. These results suggest that thermal hyperalgesia and allodynia and behavioral hyperalgesia in diabetic mice may be due to the activation of protein kinase C in the spinal cord. Considering these findings, we hypothesized that the functional abnormalities in TTX-R sodium channels and protein kinase C activities in diabetic animals may cause increased fenvalerate-induced nociception. To test this hypothesis, we examined the effect of diabetes on the fenvalerate-induced nociceptive response.
food and water in an animal room that was maintained at 2461 8C with a 12-h light–dark cycle. The animals were rendered diabetic by an injection of streptozotocin (200 mg / kg, i.v.) prepared in 0.1 N citrate buffer at pH 4.5. Age-matched non-diabetic mice were injected with the vehicle alone. The experiments were conducted 2 weeks after the injection of streptozotocin or vehicle. Mice with serum glucose levels above 4000 mg / l were considered diabetic. This study was carried out in accordance with the Declaration of Helsinki and with the ‘Guide for the Care and Use of Laboratory Animals’ as adopted by the committee on the care and use of laboratory animals of Hoshi University, which is accredited by the Ministry of Education, Science, Sports and Culture.
2.2. Nociceptive responses 2.2.1. Intrathecal injection This experiment was performed according to the method described by Hylden and Wilcox [16]. Each mouse was acclimated to an acrylic observation chamber (39326324 cm 3 ) for at least 5 min before the injection of an fenvalerate. Immediately following the injection, the mice were placed in the observation chamber. The cumulative duration (s) of biting, paw licking and scratching episodes was measured for 30 min after the injection of fenvalerate. Intrathecal (i.t.) administration was performed following the method described by Hylden and Wilcox [15]. Each i.t. injection was administered using a 30-gauge needle directly through the intact skin between the L5 and L6 vertebrae. Drugs were given in a volume of 5 ml / mouse. 2.2.2. Intraplantar injection This experiment was performed according to the method described by Shibata et al. [39]. Each mouse was acclimated to an acrylic observation chamber (32323317 cm 3 ) for at least 5 min before the injection of fenvalerate. Then, 2 ml of a solution of fenvalerate in 0.4% DMSO was administered into the dorsal surface of the right hindpaw. Immediately after the injection, each animal was returned to the observation chamber and its nociceptive response was recorded for 30 min. The mouse licked and bit the injected paw, and these responses were distinct and easily observed. The accumulated response time (s), i.e. the duration of licking and biting of the injected paw, was measured for each 5-min block. 2.3. Drugs
2. Materials and methods
2.1. Animals Male ICR mice (Tokyo Laboratory Animals Science Co., Tokyo, Japan), weighing about 20 g at the beginning of the experiments, were used. They had free access to
Fenvalerate, calphostin C and phorbol-12, 13-dibutyrate were purchased from Calbiochem-Novabiochem Corporation (La Jolla, CA, USA). Fenvalerate was dissolved in 0.4% DMSO in saline. Calphostin C and phorbol-12, 13-dibutyrate were dissolved in 0.1% ethanol in saline. Calphostin C and phorbol-12, 13-dibutyrate were injected i.t. 60 min prior to the injection of fenvalerate. The dose
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and schedule for calphostin C and phorbol-12, 13-dibutyrate in this study were determined as described previously [27,30].
2.4. Data analysis The data are expressed as mean6S.E. The statistical significance of differences between groups was assessed with an analysis of variance (ANOVA) followed by the Bonferroni–Dunnet test.
3. Results
3.1. Behavioral response induced by intrathecal fenvalerate Intrathecal injection of fenvalerate elicited a characteristic behavioral syndrome mainly consisting of reciprocal hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs in mice. This behavioral response induced by fenvalerate at a dose of 3 mg peaked at 10–20 min and almost disappeared 30 min after injection. Therefore, in subsequent experiments the mice were observed for 30 min after the injection of fenvalerate (3 mg). As shown in Fig. 1 (left panel), fenvalerate, at doses of 0.1–1 mg, i.t., dose-dependently enhanced the duration of these nociceptive responses. In diabetic mice, intrathecal injection of fenvalerate also elicited a characteristic nociceptive behavioral syndrome, as in non-diabetic mice. However, the intensity of fenvalerate-induced nociceptive responses was significantly greater in diabetic mice than in non-diabetic mice. Indeed, as shown in Fig. 1 (right panel), fenvalerate, at doses of 0.01–0.1 mg, i.t., dose-dependently enhanced the duration
Fig. 1. Duration of the nociceptive response induced by the intrathecal administration of fenvalerate in non-diabetic and diabetic mice. Data are expressed as the total duration of the response during the 30-min period after injection. Each column represents the mean with S.E. (n510). * P,0.05 vs. respective vehicle-treated group (Vehicle).
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of these nociceptive responses to the levels observed in non-diabetic mice.
3.2. Effects of protein kinase C modulators on fenvalerate-induced nociceptive behavior In diabetic mice, calphostin C (3 pmol, i.t.), a selective protein kinase C inhibitor, when administered before fenvalerate, caused a significantly inhibited fenvalerateinduced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in non-diabetic mice (Fig. 2). On the other hand, in non-diabetic mice, phorbol-12, 13-dibutyrate (50 pmol, i.t.), a protein kinase C activator, significantly enhanced fenvalerate-induced nociceptive behavior (Fig. 2). Indeed, when non-diabetic mice were pretreated with PDBu, the dose–response curve for fenvalerate-induced nociceptive behavior was shifted leftward to the level observed in diabetic mice. However, neither calphostin C nor phorbol-12, 13-dibutyrate, by themselves, produced any significant behavioral changes.
3.3. Behavioral response induced by intraplantar fenvalerate Intraplantar injection of fenvalerate elicited a characteristic behavioral syndrome mainly consisting of scratching, biting or licking of the injected hind legs, and dose-
Fig. 2. Effects of i.t. administration of calphostin C and phorbol 12,13dibutyrate (PDBu) on the fenvalerate-induced nociceptive response in non-diabetic and diabetic mice. Calphostin C (3 pmol), PDBu (50 pmol) or vehicle was injected i.t. 60 min before testing. Values are shown: vehicle-treated non-diabetic mice (open circle), vehicle-treated diabetic mice (closed circle), calphostin C-treated non-diabetic mice (open triangle), calphostin C-treated diabetic mice (closed triangle) and PDButreated non-diabetic mice (open square). Each point represents the mean with S.E. (n510–12).
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(30–100 ng) dose-dependently inhibited intraplantar fenvalerate-induced nociceptive behavior in both diabetic and non-diabetic mice.
4. Discussion
Fig. 3. Duration of the nociceptive response induced by the intraplantar (i.pl.) administration of fenvalerate in non-diabetic and diabetic mice. Data are expressed as the total duration of the response during the 30-min period after injection. Each column represents the mean with S.E. (n5 10). * P,0.05 vs. respective vehicle-treated group (Vehicle). [ P,0.05 vs. respective value of non-diabetic mice.
dependently enhanced the duration of these nociceptive responses, at doses of 0.3, 0.56 and 1 mg, in both nondiabetic and diabetic mice (Fig. 3). Diabetic mice were more sensitive to injection via this intraplantar route since fenvalerate (1 mg)-induced nociceptive responses in diabetic mice were significantly greater than those in nondiabetic mice. Fig. 4 shows the effect of mexiletine, a sodium channel blocker, on intraplantar fenvalerate-induced behavior. Intraplantar pretreatment with mexiletine
Fig. 4. Effect of intraplantar (i.pl.) administration of mexiletine on the nociceptive response induced by i.pl. fenvalerate in non-diabetic and diabetic mice. Mexiletine was injected i.pl. 30 min before fenvalerate (1 mg) injection. Data are expressed as the total duration of the response during the 30-min period after fenvalerate injection. Each column represents the mean with S.E. (n510). * P,0.05 vs. respective vehicletreated group (open column).
In the present study, we found that i.t.-administered fenvalerate produced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs. The duration of the i.t. fenvalerate-induced characteristic behavioral response in diabetic mice was significantly longer than that in non-diabetic mice. Recently, we found that i.t.-administered fenvalerate produced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs [20]. Pretreatment with i.p. morphine (1–10 mg / kg) reduced fenvalerate-induced behavior in a dose-dependent manner [20]. Furthermore, we also demonstrated that fenvalerateinduced behavior was dose-dependently reduced by mexiletine (10 and 30 mg / kg, i.p.), a lidocaine-like sodium channel blocker [20]. Therefore, these results lead us to suggest that fenvalerate-induced behavior may be related to nociception caused by the activation of sodium channels. Furthermore, we also showed that i.t. pretreatment with MK-801, an NMDA channel antagonist, caused a dose-dependent inhibition of fenvalerate-induced nociceptive responses [20]. Moreover, the fenvalerate-induced nociceptive response has also been shown to be inhibited by GR82334, a non-peptidic NK-1 receptor antagonist [20]. Based on these results, we concluded that the fenvalerate-induced nociceptive response may be mediated through the release of glutamate and neurokinins, which cause the activation of NMDA and NK-1 receptors, by acting on sodium channels [20]. It has been suggested that, as with other models of neuropathic pain, diabetic peripheral neuropathy may induce chronic changes within the spinal cord that lead to an increase in glutamate release and subsequent activation of NMDA receptors [9]. Furthermore, we previously reported that streptozotocin-induced diabetic mice show a selective change in their neuronal system that involves substance P in the spinal cord [19]. We also suggested that the release of excessive amounts of substance P from the spinal cord may be associated with the abnormalities in nociceptive transmission in mice with diabetes [19]. Therefore, it seems likely that the neuropathic pain, such as allodynia and hyperalgesia, seen in diabetic mice may be due to an increased responsiveness of primary afferent fibers followed by the activation of sodium channels. A TTX-R sodium channel current appears to be primarily responsible for action potential generation in the cell body and terminals of nociceptive afferents
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[11,12,18,21,22,35,41]. Furthermore, nerve terminals in distal limb neuromas and skin from patients with chronic local hyperalgesia and allodynia all show marked increases in TTX-R sodium channel-immunoreactive fibers, suggesting that a TTX-R sodium channel may be related to persistent nociceptive hypersensitivity. Moreover, a TTXR sodium channel is predominantly expressed in the capsaicin-sensitive small neurons of the dorsal root ganglion. Therefore, a TTX-R sodium channel appears to play an important role in nociceptive transmission [1,3,18,28,34–36,43], and especially in allodynia and hyperalgesia [33]. Based on these results, it is possible that the fenvalerate-induced nociceptive response and thermal allodynia / hyperalgesia may be mediated through the activation of TTX-R sodium channels. However, although the mode of action is different, fenvalerate is known to modulate both TTX-R and TTX-S sodium channels in a similar direction [40]. We recently demonstrated that the fenvalerate-induced nociceptive response was inhibited by the pretreatment with calphostin C, a selective protein kinase C inhibitor [20]. In contrast, the fenvalerate-induced nociceptive response was enhanced when protein kinase C was activated by phorbol-12, 13-dibutyrate [20]. Thio and Sontheimer [44] reported that the activation of protein kinase C by phorbol 12-myristate 13-acetate had different effects on TTX-S and TTX-R sodium currents. They reported that phorbol 12-myristate 13-acetate reduced peak TTX-S sodium currents by 25–60% and potentiated peak TTX-R sodium currents by 60–150% [44]. TTX-R current activation was faster and current inactivation changed from a single- to a bi-exponential after exposure to phorbol 12-myristate 13-acetate, suggesting that protein kinase C phosphorylation may have activated formerly quiescent sodium channels [44]. In contrast, TTX-S current activation was unchanged, and current inactivation decreased by an average of 50% following exposure to phorbol 12myristate 13-acetate [44]. Similarly, it has been reported that the activation of protein kinase C increased TTX-R sodium current, whereas inhibitors of protein kinase C decreased TTX-R sodium current [11]. Moreover, epinephrine-induced mechanical and thermal hyperalgesia, and epinephrine-induced enhancement of TTX-R sodium current in cultured rat dorsal root ganglion neurons, are reportedly inhibited by a protein kinase C inhibitor [22]. Based on these results, we suggested that the activation of TTX-R sodium channels is necessary to produce a fenvalerate-induced nociceptive response [20]. Activation of protein kinase C has been implicated in changes in pain perception. Phorbol esters, which activate protein kinase C, enhance the number of electrical impulses of knee joint afferents in response to passive joint movement [37] and enhance nociceptive responses after tissue injury induced by formalin [6]. In addition, noxious thermal and mechanical stimuli increase the activation of protein kinase C in the dorsal horn of the spinal cord [25,46], and the activation of protein kinase C increases the release of
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substance P from rat sensory neurons [4]. Furthermore, activation of protein kinase C by phorbol esters or intrathecal injection of protein kinase C increases the release of excitatory amino acids in dorsal horn slices [10]. Thus, the protein kinase C-induced enhancement of neurotransmitter release may underlie the neuronal sensitization that produces hyperalgesia. Many investigators have reported that hyperglycemia or elevated glucose levels can increase diacylglycerol levels and activate protein kinase C in vascular tissue, cardiac tissues or cultured cells [8,17,23,42]. Activation of the diacylglycerol–protein kinase C cellular signal pathway has been linked to vasculature dysfunction in diabetes [8,38,45]. Furthermore, Allgren and Levine [2] reported that both the mechanical behavioral hyperalgesia and C-fiber hyperexcitability seen in streptozotocin-induced diabetic rats in response to mechanical stimuli are reduced by agents that inhibit protein kinase C. In the present study, we observed that, in diabetic mice, calphostin C, a selective protein kinase C inhibitor, when administered before fenvalerate, caused a significant inhibition of fenvalerate-induced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in non-diabetic mice. On the other hand, in non-diabetic mice, phorbol-12, 13-dibutyrate, a protein kinase C activator, significantly enhanced fenvalerate-induced nociceptive behavior with a leftward shifted of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in diabetic mice. Thus, it is possible that the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice may result from a secondary effect in response to the sensitization of TTX-R sodium channels by the long-term activation of protein kinase C. In the present study, we also observed that intraplantar administration of fenvalerate elicited nociceptive behaviors. As with the intrathecal administration of fenvalerate [20], intraplantar fenvalerale-induced nociceptive behavior was dose-dependently reduced by the intraplantar application of mexiletine, a lidocaine-like sodium channel blocker, suggesting that fenvalerate may elicit nociceptive responses through the activation of sodium channels, probably TTX-R sodium channels at peripheral nociceptors. In conclusion, our findings indicate that the intrathecal and intraplantar administration of fenvalerate, a type II pyrethroid, induces a marked nociceptive response in diabetic mice compared to that in non-diabetic mice, and suggest that the sensitization of TTX-R sodium channels by the long-term activation of protein kinase C may play an important role in the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice. Furthermore, we also demonstrated that fenvalerate may elicit the nociceptive responses through the activation of sodium channels, probably TTX-R sodium channels, not only at spinal synapses but also at peripheral nociceptors.
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Acknowledgements This study was supported, in part, by a Grant-in-Aid-for Scientific Research (C) from the Ministry of Education, Culture, Sports, Science and Technology in Japan (No. 13672403).
References [1] A.N. Akopian, L. Sivilotti, J.N. Wood, A tetrodotoxin-resistant voltage-gated sodium channel expressed by sensory neurons, Nature 379 (1996) 257–262. [2] S.C. Allgren, J.D. Levine, Protein kinase C inhibitors decrease hyperalgesia and C-fiber hyperexcitability in streptozotocin-diabetic rat, J. Neurophysiol. 72 (1994) 684–692. [3] J.B. Arbuckle, R.J. Docherty, Expression of tetrodotoxin-resistant sodium channels in capsaicin-sensitive dorsal root ganglion neurons of adult rats, Neurosci. Lett. 185 (1995) 70–73. [4] L.A. Barber, M.R. Vasko, Activation of protein kinase C augments peptide release from rat sensory neurons, J. Neurochem. 67 (1996) 72–80. [5] W.A. Catterall, Neurotoxins that act on voltage-sensitive sodium channels in excitable membranes, Annu. Rev. Pharmacol. Toxicol. 20 (1980) 15–43. [6] T. Coderre, Contribution of protein kinase C to central sensitization and persistent pain following tissue injury, Neurosci. Lett. 140 (1992) 181–184. [7] J.F. Cotton, M.J. Welsh, Covalent modification of the regulatory domain irreversible stimulates cystic fibrosis transmembrane conductance regulator, J. Biol. Chem. 272 (1997) 25617–25622. [8] P.A. Craven, F.R. De Rubertis, Protein kinase C is activated in glomeruli from streptozotocin diabetic rats, J. Clin. Invest. 83 (1989) 1667–1675. [9] S.N. Davies, D. Lodge, Evidence for involvement of N-methyl-Daspartate receptors in wind-up of class 2 neurons in the dorsal horn of the rat, Brain Res. 424 (1987) 402–406. [10] G. Gerber, I. Kangrga, P.D. Ryu, M. Larew, M. Randic, Multiple effects of phorbol esters in the rat spinal dorsal horn, J. Neurosci. 9 (1989) 3606–3617. [11] M.S. Gold, J.D. Levine, A.M. Correa, Modulation of TTX-R INa by PKC and PKA and their role in PGE2-induced sensitization of rat sensory neurons in vitro, J. Neurosci. 18 (1998) 10345–10355. [12] J.G. Gu, A.B. Macdermott, Activation of ATP P2X receptors elicits glutamate release from sensory neuron synapses, Nature 389 (1997) 749–753. [13] M. Hirade, H. Yasuda, M. Omatsu-Kanbe, R. Kikkawa, H. Kitasato, Tetrodotoxin-resistant sodium channels of dorsal root ganglion neurons are readily activated in diabetic rats, Neuroscience 90 (1990) 933–939. [14] K. Hoehn, T.W. Watson, B.A. Macvicar, A novel tetrodotoxininsensitive, slow sodium current in striatal and hippocampal neurons, Neuron 10 (1993) 543–552. [15] J.K.L. Hylden, G.L. Wilcox, Intrathecal morphine in mice: a new technique, Eur. J. Pharmacol. 67 (1980) 313–316. [16] J.K.L. Hylden, G.L. Wilcox, Intrathecal substance P elicits a caudally-directed biting and scratching behavior, Brain Res. 217 (1981) 212–215. [17] T. Inoguchi, R. Battan, E. Handler, J.R. Sportsman, W. Health, G.L. King, Preferential elevation of protein kinase C isoform bII and diacylglycerol levels in the aorta and heart of diabetic rats: differential reversibility to glycemic control by islet cell transplantation, Proc. Natl. Acad. Sci. USA 89 (1992) 11059–11063. [18] S. Jeftinija, The role of tetrodotoxin-resistant sodium channels of small primary afferent fibers, Brain Res. 639 (1994) 125–134.
[19] J. Kamei, Y. Ohhashi, T. Aoki, Y. Kasuya, Streptozotocin-induced diabetes in mice reduces the nociceptive threshold, as recognized after application of noxious mechanical stimuli but not for thermal stimuli, Pharmacol. Biochem. Behav. 39 (1991) 541–544. [20] J. Kamei, M. Sasaki, K. Zushida, S. Tanaka, Nociception and allodynia / hyperalgesia induced by intrathecal administration of fenvalerate, Jpn. J. Pharmacol. 86 (2001) 336–341. [21] S.G. Khasar, M.S. Gold, J.D. Levine, A tetrodotoxin-resistant sodium current mediates inflammatory pain in the rat, Neurosci. Lett. 256 (1998) 17–20. [22] S.G. Khasar, Y.H. Lin, A. Martin, J. Gadgar, T. Mcmahon, D. Wang, B. Hundle, K.O. Aley, W. Isenberg, G. Mccarter, P.G. Green, C.W. Hodge, J.D. Levine, R.O. Messing, A novel nociceptor signaling pathway revealed in protein kinase C epsilon mutant mice, Neuron 24 (1990) 253–260. [23] G.L. King, S. Johnson, G. Wu, Possible growth modulators involved in the pathogenesis of diabetic proliferative retinopathy, in: B. Westermark, C. Betscholtz, T. Hokfelt (Eds.), Growth Factors in Health and Diseases, Elsevier, Amsterdam, 1990, pp. 303–317. [24] P.G. Kostyuk, N.S. Veselovsky, Y.A. Tsyndrenko, Ionic currents in the somatic membrane of rat dorsal root ganglion neurons: I Sodium currents, Neuroscience 6 (1981) 2423–2430. [25] J. Mao, D.D. Price, D.J. Mayer, R.L. Hayes, Pain-related increases in spinal cord membrane-bound protein kinase C following peripheral nerve injury, Brain Res. 588 (1992) 144–149. [26] M.J. Mclean, P.B. Bennett, R.M. Thomas, Subtypes of dorsal root ganglion neurons based on different inward currents as measured by whole-cell voltage clamp, Mol. Cell. Biochem. 80 (1988) 95–107. [27] M. Narita, M. Ohsawa, H. Mizoguchi, J. Kamei, L.F. Tseng, Pretreatment with protein kinase C activator phorbol 12,13-dibutyrate attenuates the antinociception induced by m- but not ´opioid receptor agonist in the mouse, Neuroscience 76 (1997) 291–298. [28] S.D. Novakovic, E. Tzoumaka, J.G. McGivern, M. Haraguchi, L. Sangameswaran, K.R. Gogas, R.M. Eglen, J.C. Hunter, Distribution of the tetrodotoxin-resistant sodium channel PN3 in rat sensory neurons in normal and neuropathic conditions, J. Neurosci. 18 (1998) 2174–2187. [29] N. Ogata, H. Tatebayashi, Kinetic analysis of two types of Na 1 channels in rat dorsal root ganglia, J. Physiol. (Lond.) 466 (1993) 9–37. [30] M. Ohsawa, J. Kamei, Possible involvement of protein kinase C in the attenuation of DAMGO-induced antinociception in diabetic mice, Eur. J. Pharmacol. 339 (1997) 27–31. [31] M. Ohsawa, J. Kamei, Possible involvement of spinal protein kinase C in the thermal allodynia and hyperalgesia in diabetic mice, Eur. J. Pharmacol. 372 (1999) 221–228. [32] M. Ohsawa, T. Kashiwazaki, J. Kamei, Modulation of the formalininduced nociceptive response by diabetes: possible involvement of protein kinase C, Brain Res. 803 (1998) 198–203. [33] F. Porecca, J. Lai, D. Bian, S. Wegert, M.H. Ossipov, R.M. Eglen, L. Kassotakis, S. Novakovic, D. Rabert, L. Sangameswaran, J.A. Hunter, Comparison of the potential role of the tetrodotoxin-insensitive sodium channels, PN3 / SNS and NaN / SNS2, in rat model of chronic pain, Proc. Natl. Acad. Sci. USA 96 (1999) 7640–7644. [34] D.K. Rabert, B.D. Koch, M. Ilnicka, R.A. Obernolte, S.L. Naylor, R.C. Herman, R.M. Eglen, J.C. Hunter, L. Sangameswaran, A tetrodotoxin-resistant voltage-gated sodium channel from human dorsal root ganglia, hPN3 / SCN10A, Pain 78 (1998) 107–114. [35] A.M. Ritter, I.M. Mendell, Somal membrane properties of physiologically identified sensory neurons in the rat: effects of nerve growth factor, J. Neurophysiol. 68 (1992) 2033–2041. [36] L. Sangameswaran, S.G. Delgado, L.M. Fish, B.D. Koch, L.B. Jakeman, G.R. Stewart, P. Sze, J.C. Hunter, R.M. Eglen, R.C. Herman, Structure and function of a novel voltage-gated tetrodotoxin-resistant sodium channel specific to sensory neurons, J. Biol. Chem. 271 (1996) 5953–5956.
J. Kamei et al. / Brain Research 948 (2002) 17 – 23 [37] K. Schepelmann, K. Meßlinger, R.F. Schmidt, The effects of phorbol ester on slowly conducting afferents of the cat’s knee joint, Exp. Brain Res. 92 (1993) 391–398. [38] T. Shiba, T. Inoguchi, R. Sportsman, W. Health, S.E. Bursell, G.L. King, Correlation of diacylglycerol level and protein kinase C activity in rat retina to retinal circulation, Am. J. Physiol. 265 (1993) E787–E793. [39] M. Shibata, T. Ohkubo, H. Takahashi, R. Inoki, Modified formalin test: characteristic biphasic pain response, Pain 38 (1989) 347–352. [40] J.H. Song, K. Nagata, H. Tatebayashi, T. Narahashi, Interaction of tetramethrin, fenvalerate and DDT at the sodium channel in rat dorsal root ganglion neurons, Brain Res. 708 (1996) 29–37. [41] A.M. Strassman, S.A. Raymond, Electrophysiological evidence for tetrodotoxin-resistant sodium channels in slowly conducting dural sensory fibers, J. Neurophysiol. 81 (1999) 413–424. [42] A. Tanaka, Y. Kashiwagi, T. Ogawa, N. Abe, T. Asahina, M. Ikebuchi, Y. Takagi, Y. Shigeta, Effect of verapamil on cardiac protein kinase C activity in diabetic rats, Eur. J. Pharmacol. 200 (1991) 353–356.
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[43] S. Tate, S. Benn, C. Hick, D. Trezise, V. John, R.J. Mannion, M. Costigan, C. Plumpton, D. Grose, Z. Gladwell, G. Kendall, K. Dale, C. Bountra, C.J. Woolf, Two sodium channels contribute to the TTX-R sodium current in primary sensory neurons, Nature Neurosci. 1 (1998) 653–655. [44] C.L. Thio, H. Sontheimer, Differential modulation of TTX-sensitive and TTX-resistant Na 1 channels in spinal cord astrocytes following activation of protein kinase C, J. Neurosci. 13 (1993) 4889–4897. [45] B.A. Wolf, J.R. Williamson, R.A. Easom, K. Chang, W.R. Sherman, J. Turk, Diacylglycerol accumulation and microvascular abnormalities induced by elevated glucose levels, J. Clin. Invest. 98 (1990) 31–38. [46] K. Yashpal, G.M. Pitcher, A. Parent, R. Quirion, T.J. Coderre, Noxious thermal and chemical stimulation induce increase in 3Hphorbol 12,13-dibutyrate binding in spinal cord dorsal horn as well as persistent pain and hyperalgesia, which is reduced by inhibition of protein kinase C, J. Neurosci. 15 (1995) 3263–3272. [47] S. Yoshida, Tetrodotoxin-resistant sodium channels, Cell Mol. Neurobiol. 14 (1994) 227–244.
Research report
Modification of the fenvalerate-induced nociceptive response in mice by diabetes Junzo Kamei a , *, Emiko Iguchi a , Mitsumasa Sasaki b , Ko Zushida a , Kayo Morita a , Shun-ichi Tanaka c a
Department of Pathophysiology and Therapeutics, Faculty of Pharmaceutical Sciences, Hoshi University, 4 -41, Ebara 2 -Chome, Shinagawa-ku, Tokyo 142 -8501, Japan b Basic Research Laboratory, HALD Inc., Yokohama 236 -0003, Japan c Department of Neurobiology of Aging Laboratories, The Mount Sinai School of Medicine, New York, NY 10029 -6574, USA Accepted 18 April 2002
Abstract We examined the effect of diabetes on the fenvalerate-induced nociceptive response in mice. The intrathecal (i.t.) or intraplantar (i.pl.) injection of fenvalerate, a sodium channel activator, induced a characteristic behavioral syndrome mainly consisting of reciprocal hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs in both non-diabetic and diabetic mice. However, the intensity of such fenvalerate-induced nociceptive responses was significantly greater in diabetic mice than in non-diabetic mice. Calphostin C (3 pmol, i.t.), a selective protein kinase C inhibitor, significantly inhibited intrathecal fenvalerate-induced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level those observed in non-diabetic mice. On the other hand, when non-diabetic mice were pretreated with phorbol-12, 13-dibutyrate (50 pmol, i.t.), the dose–response curve for intrathecal fenvalerate-induced nociceptive behavior was shifted leftward to the level those observed in diabetic mice. These results suggest that the sensitization of sodium channels, probably tetrodotoxin-resistant (TTX-R) sodium channels, by the long-term activation of protein kinase C may play an important role in the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice. 2002 Elsevier Science B.V. All rights reserved. Theme: Sensory systems Topic: Pain modulation: pharmacology Keywords: Diabetes; Nociception; Fenvalerate; TTX-R sodium channel; Protein kinase C
1. Introduction Most neuronal sodium channels can be blocked by tetrodotoxin (TTX), with Kd values of 1–10 nM. However, sodium channels that are resistant to the blocking action of TTX have been found in both the central and peripheral nervous systems [5,14,47]. Dorsal root ganglion neurons express a slow activating and inactivating TTXresistant (TTX-R) sodium channel as well as a fast activating and inactivating TTX-sensitive (TTX-S) sodium channel [7,24,26,29]. The TTX-R sodium channel is *Corresponding author. Tel.: 181-3-5498-5030; fax: 181-3-54985029. E-mail address: [email protected] (J. Kamei).
predominantly expressed in the capsaicin-sensitive small neurons of the dorsal root ganglion and appears to play an important role in nociceptive transmission [1,3,28,34,36,43], and especially in allodynia and hyperalgesia [33]. In spinal cord astrocytes, protein kinase C enhanced TTX-R sodium channels, with leftward shifts in the voltage-dependence of both activation and inactivation, and produced faster kinetics [44]. Pyrethroid insecticides are known to modulate the gating kinetics of neuronal sodium channels to cause repetitive discharges and membrane depolarization. In TTX-R sodium channels, fenvalerate, a type II pyrethroid, irreversibly prolongs the sodium current during depolarization and greatly augments and prolongs the tail current [40]. Recently, we found that i.t.-administered fenvalerate pro-
0006-8993 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. PII: S0006-8993( 02 )02944-X
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duced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs [20]. Such characteristic fenvalerate-induced behavior was inhibited by morphine, mexiletine (a sodium channel blocker), MK-801 (an N-methyl-D-aspartate ion-channel blocker), and GR82334 (a neurokinin-1 receptor antagonist) [20]. We also showed that calphostin C, a protein kinase C inhibitor, inhibited fenvalerate-induced behavior [20]. On the other hand, phorbol-12, 13-dibutyrate, a protein kinase C activator, markedly enhanced the fenvalerate-induced behavior [20]. Based on these results, we suggested that the intrathecal administration of fenvalerate induces a marked nociceptive response and thermal allodynia / hyperalgesia, and suggested that TTX-R sodium channels may play an important role in this effect [20]. Hirade et al. [13] recently described the functional changes in TTX-R sodium channel activity of dorsal ganglion neurons in diabetic rats. Based on an increase in current density and a leftward shift of voltage-dependence of gating states of the TTX-R sodium channels, they proposed that TTX-R sodium channel function was altered in diabetes, which explains why neurons participating in nociception are highly excitable in diabetic animals. Allgren and Levine [2] reported that both the mechanical behavioral hyperalgesia and C-fiber hyperexcitability in response to mechanical stimuli seen in streptozotocin-induced diabetic rats are reduced by agents that inhibit protein kinase C. Furthermore, we recently reported that i.t. pretreatment with a protein kinase C inhibitor, calphostin C, attenuates thermal allodynia and hyperalgesia in diabetic mice [31]. On the other hand, in non-diabetic mice, thermal hyperalgesia and allodynia were caused by i.t. pretreatment with a protein kinase C activator, phorbol12, 13-dibutyrate [31]. Moreover, we also demonstrated that i.t. pretreatment with calphostin C reduced the enhanced formalin-induced nociceptive responses in diabetic mice to the level observed in non-diabetic mice [32]. These results suggest that thermal hyperalgesia and allodynia and behavioral hyperalgesia in diabetic mice may be due to the activation of protein kinase C in the spinal cord. Considering these findings, we hypothesized that the functional abnormalities in TTX-R sodium channels and protein kinase C activities in diabetic animals may cause increased fenvalerate-induced nociception. To test this hypothesis, we examined the effect of diabetes on the fenvalerate-induced nociceptive response.
food and water in an animal room that was maintained at 2461 8C with a 12-h light–dark cycle. The animals were rendered diabetic by an injection of streptozotocin (200 mg / kg, i.v.) prepared in 0.1 N citrate buffer at pH 4.5. Age-matched non-diabetic mice were injected with the vehicle alone. The experiments were conducted 2 weeks after the injection of streptozotocin or vehicle. Mice with serum glucose levels above 4000 mg / l were considered diabetic. This study was carried out in accordance with the Declaration of Helsinki and with the ‘Guide for the Care and Use of Laboratory Animals’ as adopted by the committee on the care and use of laboratory animals of Hoshi University, which is accredited by the Ministry of Education, Science, Sports and Culture.
2.2. Nociceptive responses 2.2.1. Intrathecal injection This experiment was performed according to the method described by Hylden and Wilcox [16]. Each mouse was acclimated to an acrylic observation chamber (39326324 cm 3 ) for at least 5 min before the injection of an fenvalerate. Immediately following the injection, the mice were placed in the observation chamber. The cumulative duration (s) of biting, paw licking and scratching episodes was measured for 30 min after the injection of fenvalerate. Intrathecal (i.t.) administration was performed following the method described by Hylden and Wilcox [15]. Each i.t. injection was administered using a 30-gauge needle directly through the intact skin between the L5 and L6 vertebrae. Drugs were given in a volume of 5 ml / mouse. 2.2.2. Intraplantar injection This experiment was performed according to the method described by Shibata et al. [39]. Each mouse was acclimated to an acrylic observation chamber (32323317 cm 3 ) for at least 5 min before the injection of fenvalerate. Then, 2 ml of a solution of fenvalerate in 0.4% DMSO was administered into the dorsal surface of the right hindpaw. Immediately after the injection, each animal was returned to the observation chamber and its nociceptive response was recorded for 30 min. The mouse licked and bit the injected paw, and these responses were distinct and easily observed. The accumulated response time (s), i.e. the duration of licking and biting of the injected paw, was measured for each 5-min block. 2.3. Drugs
2. Materials and methods
2.1. Animals Male ICR mice (Tokyo Laboratory Animals Science Co., Tokyo, Japan), weighing about 20 g at the beginning of the experiments, were used. They had free access to
Fenvalerate, calphostin C and phorbol-12, 13-dibutyrate were purchased from Calbiochem-Novabiochem Corporation (La Jolla, CA, USA). Fenvalerate was dissolved in 0.4% DMSO in saline. Calphostin C and phorbol-12, 13-dibutyrate were dissolved in 0.1% ethanol in saline. Calphostin C and phorbol-12, 13-dibutyrate were injected i.t. 60 min prior to the injection of fenvalerate. The dose
J. Kamei et al. / Brain Research 948 (2002) 17 – 23
and schedule for calphostin C and phorbol-12, 13-dibutyrate in this study were determined as described previously [27,30].
2.4. Data analysis The data are expressed as mean6S.E. The statistical significance of differences between groups was assessed with an analysis of variance (ANOVA) followed by the Bonferroni–Dunnet test.
3. Results
3.1. Behavioral response induced by intrathecal fenvalerate Intrathecal injection of fenvalerate elicited a characteristic behavioral syndrome mainly consisting of reciprocal hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs in mice. This behavioral response induced by fenvalerate at a dose of 3 mg peaked at 10–20 min and almost disappeared 30 min after injection. Therefore, in subsequent experiments the mice were observed for 30 min after the injection of fenvalerate (3 mg). As shown in Fig. 1 (left panel), fenvalerate, at doses of 0.1–1 mg, i.t., dose-dependently enhanced the duration of these nociceptive responses. In diabetic mice, intrathecal injection of fenvalerate also elicited a characteristic nociceptive behavioral syndrome, as in non-diabetic mice. However, the intensity of fenvalerate-induced nociceptive responses was significantly greater in diabetic mice than in non-diabetic mice. Indeed, as shown in Fig. 1 (right panel), fenvalerate, at doses of 0.01–0.1 mg, i.t., dose-dependently enhanced the duration
Fig. 1. Duration of the nociceptive response induced by the intrathecal administration of fenvalerate in non-diabetic and diabetic mice. Data are expressed as the total duration of the response during the 30-min period after injection. Each column represents the mean with S.E. (n510). * P,0.05 vs. respective vehicle-treated group (Vehicle).
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of these nociceptive responses to the levels observed in non-diabetic mice.
3.2. Effects of protein kinase C modulators on fenvalerate-induced nociceptive behavior In diabetic mice, calphostin C (3 pmol, i.t.), a selective protein kinase C inhibitor, when administered before fenvalerate, caused a significantly inhibited fenvalerateinduced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in non-diabetic mice (Fig. 2). On the other hand, in non-diabetic mice, phorbol-12, 13-dibutyrate (50 pmol, i.t.), a protein kinase C activator, significantly enhanced fenvalerate-induced nociceptive behavior (Fig. 2). Indeed, when non-diabetic mice were pretreated with PDBu, the dose–response curve for fenvalerate-induced nociceptive behavior was shifted leftward to the level observed in diabetic mice. However, neither calphostin C nor phorbol-12, 13-dibutyrate, by themselves, produced any significant behavioral changes.
3.3. Behavioral response induced by intraplantar fenvalerate Intraplantar injection of fenvalerate elicited a characteristic behavioral syndrome mainly consisting of scratching, biting or licking of the injected hind legs, and dose-
Fig. 2. Effects of i.t. administration of calphostin C and phorbol 12,13dibutyrate (PDBu) on the fenvalerate-induced nociceptive response in non-diabetic and diabetic mice. Calphostin C (3 pmol), PDBu (50 pmol) or vehicle was injected i.t. 60 min before testing. Values are shown: vehicle-treated non-diabetic mice (open circle), vehicle-treated diabetic mice (closed circle), calphostin C-treated non-diabetic mice (open triangle), calphostin C-treated diabetic mice (closed triangle) and PDButreated non-diabetic mice (open square). Each point represents the mean with S.E. (n510–12).
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(30–100 ng) dose-dependently inhibited intraplantar fenvalerate-induced nociceptive behavior in both diabetic and non-diabetic mice.
4. Discussion
Fig. 3. Duration of the nociceptive response induced by the intraplantar (i.pl.) administration of fenvalerate in non-diabetic and diabetic mice. Data are expressed as the total duration of the response during the 30-min period after injection. Each column represents the mean with S.E. (n5 10). * P,0.05 vs. respective vehicle-treated group (Vehicle). [ P,0.05 vs. respective value of non-diabetic mice.
dependently enhanced the duration of these nociceptive responses, at doses of 0.3, 0.56 and 1 mg, in both nondiabetic and diabetic mice (Fig. 3). Diabetic mice were more sensitive to injection via this intraplantar route since fenvalerate (1 mg)-induced nociceptive responses in diabetic mice were significantly greater than those in nondiabetic mice. Fig. 4 shows the effect of mexiletine, a sodium channel blocker, on intraplantar fenvalerate-induced behavior. Intraplantar pretreatment with mexiletine
Fig. 4. Effect of intraplantar (i.pl.) administration of mexiletine on the nociceptive response induced by i.pl. fenvalerate in non-diabetic and diabetic mice. Mexiletine was injected i.pl. 30 min before fenvalerate (1 mg) injection. Data are expressed as the total duration of the response during the 30-min period after fenvalerate injection. Each column represents the mean with S.E. (n510). * P,0.05 vs. respective vehicletreated group (open column).
In the present study, we found that i.t.-administered fenvalerate produced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs. The duration of the i.t. fenvalerate-induced characteristic behavioral response in diabetic mice was significantly longer than that in non-diabetic mice. Recently, we found that i.t.-administered fenvalerate produced a characteristic behavioral response mainly consisting of hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs [20]. Pretreatment with i.p. morphine (1–10 mg / kg) reduced fenvalerate-induced behavior in a dose-dependent manner [20]. Furthermore, we also demonstrated that fenvalerateinduced behavior was dose-dependently reduced by mexiletine (10 and 30 mg / kg, i.p.), a lidocaine-like sodium channel blocker [20]. Therefore, these results lead us to suggest that fenvalerate-induced behavior may be related to nociception caused by the activation of sodium channels. Furthermore, we also showed that i.t. pretreatment with MK-801, an NMDA channel antagonist, caused a dose-dependent inhibition of fenvalerate-induced nociceptive responses [20]. Moreover, the fenvalerate-induced nociceptive response has also been shown to be inhibited by GR82334, a non-peptidic NK-1 receptor antagonist [20]. Based on these results, we concluded that the fenvalerate-induced nociceptive response may be mediated through the release of glutamate and neurokinins, which cause the activation of NMDA and NK-1 receptors, by acting on sodium channels [20]. It has been suggested that, as with other models of neuropathic pain, diabetic peripheral neuropathy may induce chronic changes within the spinal cord that lead to an increase in glutamate release and subsequent activation of NMDA receptors [9]. Furthermore, we previously reported that streptozotocin-induced diabetic mice show a selective change in their neuronal system that involves substance P in the spinal cord [19]. We also suggested that the release of excessive amounts of substance P from the spinal cord may be associated with the abnormalities in nociceptive transmission in mice with diabetes [19]. Therefore, it seems likely that the neuropathic pain, such as allodynia and hyperalgesia, seen in diabetic mice may be due to an increased responsiveness of primary afferent fibers followed by the activation of sodium channels. A TTX-R sodium channel current appears to be primarily responsible for action potential generation in the cell body and terminals of nociceptive afferents
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[11,12,18,21,22,35,41]. Furthermore, nerve terminals in distal limb neuromas and skin from patients with chronic local hyperalgesia and allodynia all show marked increases in TTX-R sodium channel-immunoreactive fibers, suggesting that a TTX-R sodium channel may be related to persistent nociceptive hypersensitivity. Moreover, a TTXR sodium channel is predominantly expressed in the capsaicin-sensitive small neurons of the dorsal root ganglion. Therefore, a TTX-R sodium channel appears to play an important role in nociceptive transmission [1,3,18,28,34–36,43], and especially in allodynia and hyperalgesia [33]. Based on these results, it is possible that the fenvalerate-induced nociceptive response and thermal allodynia / hyperalgesia may be mediated through the activation of TTX-R sodium channels. However, although the mode of action is different, fenvalerate is known to modulate both TTX-R and TTX-S sodium channels in a similar direction [40]. We recently demonstrated that the fenvalerate-induced nociceptive response was inhibited by the pretreatment with calphostin C, a selective protein kinase C inhibitor [20]. In contrast, the fenvalerate-induced nociceptive response was enhanced when protein kinase C was activated by phorbol-12, 13-dibutyrate [20]. Thio and Sontheimer [44] reported that the activation of protein kinase C by phorbol 12-myristate 13-acetate had different effects on TTX-S and TTX-R sodium currents. They reported that phorbol 12-myristate 13-acetate reduced peak TTX-S sodium currents by 25–60% and potentiated peak TTX-R sodium currents by 60–150% [44]. TTX-R current activation was faster and current inactivation changed from a single- to a bi-exponential after exposure to phorbol 12-myristate 13-acetate, suggesting that protein kinase C phosphorylation may have activated formerly quiescent sodium channels [44]. In contrast, TTX-S current activation was unchanged, and current inactivation decreased by an average of 50% following exposure to phorbol 12myristate 13-acetate [44]. Similarly, it has been reported that the activation of protein kinase C increased TTX-R sodium current, whereas inhibitors of protein kinase C decreased TTX-R sodium current [11]. Moreover, epinephrine-induced mechanical and thermal hyperalgesia, and epinephrine-induced enhancement of TTX-R sodium current in cultured rat dorsal root ganglion neurons, are reportedly inhibited by a protein kinase C inhibitor [22]. Based on these results, we suggested that the activation of TTX-R sodium channels is necessary to produce a fenvalerate-induced nociceptive response [20]. Activation of protein kinase C has been implicated in changes in pain perception. Phorbol esters, which activate protein kinase C, enhance the number of electrical impulses of knee joint afferents in response to passive joint movement [37] and enhance nociceptive responses after tissue injury induced by formalin [6]. In addition, noxious thermal and mechanical stimuli increase the activation of protein kinase C in the dorsal horn of the spinal cord [25,46], and the activation of protein kinase C increases the release of
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substance P from rat sensory neurons [4]. Furthermore, activation of protein kinase C by phorbol esters or intrathecal injection of protein kinase C increases the release of excitatory amino acids in dorsal horn slices [10]. Thus, the protein kinase C-induced enhancement of neurotransmitter release may underlie the neuronal sensitization that produces hyperalgesia. Many investigators have reported that hyperglycemia or elevated glucose levels can increase diacylglycerol levels and activate protein kinase C in vascular tissue, cardiac tissues or cultured cells [8,17,23,42]. Activation of the diacylglycerol–protein kinase C cellular signal pathway has been linked to vasculature dysfunction in diabetes [8,38,45]. Furthermore, Allgren and Levine [2] reported that both the mechanical behavioral hyperalgesia and C-fiber hyperexcitability seen in streptozotocin-induced diabetic rats in response to mechanical stimuli are reduced by agents that inhibit protein kinase C. In the present study, we observed that, in diabetic mice, calphostin C, a selective protein kinase C inhibitor, when administered before fenvalerate, caused a significant inhibition of fenvalerate-induced nociceptive behavior with a rightward shift of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in non-diabetic mice. On the other hand, in non-diabetic mice, phorbol-12, 13-dibutyrate, a protein kinase C activator, significantly enhanced fenvalerate-induced nociceptive behavior with a leftward shifted of the dose–response curve for fenvalerate-induced nociceptive behavior to the level observed in diabetic mice. Thus, it is possible that the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice may result from a secondary effect in response to the sensitization of TTX-R sodium channels by the long-term activation of protein kinase C. In the present study, we also observed that intraplantar administration of fenvalerate elicited nociceptive behaviors. As with the intrathecal administration of fenvalerate [20], intraplantar fenvalerale-induced nociceptive behavior was dose-dependently reduced by the intraplantar application of mexiletine, a lidocaine-like sodium channel blocker, suggesting that fenvalerate may elicit nociceptive responses through the activation of sodium channels, probably TTX-R sodium channels at peripheral nociceptors. In conclusion, our findings indicate that the intrathecal and intraplantar administration of fenvalerate, a type II pyrethroid, induces a marked nociceptive response in diabetic mice compared to that in non-diabetic mice, and suggest that the sensitization of TTX-R sodium channels by the long-term activation of protein kinase C may play an important role in the enhancement of the duration of fenvalerate-induced nociceptive behavior in diabetic mice. Furthermore, we also demonstrated that fenvalerate may elicit the nociceptive responses through the activation of sodium channels, probably TTX-R sodium channels, not only at spinal synapses but also at peripheral nociceptors.
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J. Kamei et al. / Brain Research 948 (2002) 17 – 23
Acknowledgements This study was supported, in part, by a Grant-in-Aid-for Scientific Research (C) from the Ministry of Education, Culture, Sports, Science and Technology in Japan (No. 13672403).
References [1] A.N. Akopian, L. Sivilotti, J.N. Wood, A tetrodotoxin-resistant voltage-gated sodium channel expressed by sensory neurons, Nature 379 (1996) 257–262. [2] S.C. Allgren, J.D. Levine, Protein kinase C inhibitors decrease hyperalgesia and C-fiber hyperexcitability in streptozotocin-diabetic rat, J. Neurophysiol. 72 (1994) 684–692. [3] J.B. Arbuckle, R.J. Docherty, Expression of tetrodotoxin-resistant sodium channels in capsaicin-sensitive dorsal root ganglion neurons of adult rats, Neurosci. Lett. 185 (1995) 70–73. [4] L.A. Barber, M.R. Vasko, Activation of protein kinase C augments peptide release from rat sensory neurons, J. Neurochem. 67 (1996) 72–80. [5] W.A. Catterall, Neurotoxins that act on voltage-sensitive sodium channels in excitable membranes, Annu. Rev. Pharmacol. Toxicol. 20 (1980) 15–43. [6] T. Coderre, Contribution of protein kinase C to central sensitization and persistent pain following tissue injury, Neurosci. Lett. 140 (1992) 181–184. [7] J.F. Cotton, M.J. Welsh, Covalent modification of the regulatory domain irreversible stimulates cystic fibrosis transmembrane conductance regulator, J. Biol. Chem. 272 (1997) 25617–25622. [8] P.A. Craven, F.R. De Rubertis, Protein kinase C is activated in glomeruli from streptozotocin diabetic rats, J. Clin. Invest. 83 (1989) 1667–1675. [9] S.N. Davies, D. Lodge, Evidence for involvement of N-methyl-Daspartate receptors in wind-up of class 2 neurons in the dorsal horn of the rat, Brain Res. 424 (1987) 402–406. [10] G. Gerber, I. Kangrga, P.D. Ryu, M. Larew, M. Randic, Multiple effects of phorbol esters in the rat spinal dorsal horn, J. Neurosci. 9 (1989) 3606–3617. [11] M.S. Gold, J.D. Levine, A.M. Correa, Modulation of TTX-R INa by PKC and PKA and their role in PGE2-induced sensitization of rat sensory neurons in vitro, J. Neurosci. 18 (1998) 10345–10355. [12] J.G. Gu, A.B. Macdermott, Activation of ATP P2X receptors elicits glutamate release from sensory neuron synapses, Nature 389 (1997) 749–753. [13] M. Hirade, H. Yasuda, M. Omatsu-Kanbe, R. Kikkawa, H. Kitasato, Tetrodotoxin-resistant sodium channels of dorsal root ganglion neurons are readily activated in diabetic rats, Neuroscience 90 (1990) 933–939. [14] K. Hoehn, T.W. Watson, B.A. Macvicar, A novel tetrodotoxininsensitive, slow sodium current in striatal and hippocampal neurons, Neuron 10 (1993) 543–552. [15] J.K.L. Hylden, G.L. Wilcox, Intrathecal morphine in mice: a new technique, Eur. J. Pharmacol. 67 (1980) 313–316. [16] J.K.L. Hylden, G.L. Wilcox, Intrathecal substance P elicits a caudally-directed biting and scratching behavior, Brain Res. 217 (1981) 212–215. [17] T. Inoguchi, R. Battan, E. Handler, J.R. Sportsman, W. Health, G.L. King, Preferential elevation of protein kinase C isoform bII and diacylglycerol levels in the aorta and heart of diabetic rats: differential reversibility to glycemic control by islet cell transplantation, Proc. Natl. Acad. Sci. USA 89 (1992) 11059–11063. [18] S. Jeftinija, The role of tetrodotoxin-resistant sodium channels of small primary afferent fibers, Brain Res. 639 (1994) 125–134.
[19] J. Kamei, Y. Ohhashi, T. Aoki, Y. Kasuya, Streptozotocin-induced diabetes in mice reduces the nociceptive threshold, as recognized after application of noxious mechanical stimuli but not for thermal stimuli, Pharmacol. Biochem. Behav. 39 (1991) 541–544. [20] J. Kamei, M. Sasaki, K. Zushida, S. Tanaka, Nociception and allodynia / hyperalgesia induced by intrathecal administration of fenvalerate, Jpn. J. Pharmacol. 86 (2001) 336–341. [21] S.G. Khasar, M.S. Gold, J.D. Levine, A tetrodotoxin-resistant sodium current mediates inflammatory pain in the rat, Neurosci. Lett. 256 (1998) 17–20. [22] S.G. Khasar, Y.H. Lin, A. Martin, J. Gadgar, T. Mcmahon, D. Wang, B. Hundle, K.O. Aley, W. Isenberg, G. Mccarter, P.G. Green, C.W. Hodge, J.D. Levine, R.O. Messing, A novel nociceptor signaling pathway revealed in protein kinase C epsilon mutant mice, Neuron 24 (1990) 253–260. [23] G.L. King, S. Johnson, G. Wu, Possible growth modulators involved in the pathogenesis of diabetic proliferative retinopathy, in: B. Westermark, C. Betscholtz, T. Hokfelt (Eds.), Growth Factors in Health and Diseases, Elsevier, Amsterdam, 1990, pp. 303–317. [24] P.G. Kostyuk, N.S. Veselovsky, Y.A. Tsyndrenko, Ionic currents in the somatic membrane of rat dorsal root ganglion neurons: I Sodium currents, Neuroscience 6 (1981) 2423–2430. [25] J. Mao, D.D. Price, D.J. Mayer, R.L. Hayes, Pain-related increases in spinal cord membrane-bound protein kinase C following peripheral nerve injury, Brain Res. 588 (1992) 144–149. [26] M.J. Mclean, P.B. Bennett, R.M. Thomas, Subtypes of dorsal root ganglion neurons based on different inward currents as measured by whole-cell voltage clamp, Mol. Cell. Biochem. 80 (1988) 95–107. [27] M. Narita, M. Ohsawa, H. Mizoguchi, J. Kamei, L.F. Tseng, Pretreatment with protein kinase C activator phorbol 12,13-dibutyrate attenuates the antinociception induced by m- but not ´opioid receptor agonist in the mouse, Neuroscience 76 (1997) 291–298. [28] S.D. Novakovic, E. Tzoumaka, J.G. McGivern, M. Haraguchi, L. Sangameswaran, K.R. Gogas, R.M. Eglen, J.C. Hunter, Distribution of the tetrodotoxin-resistant sodium channel PN3 in rat sensory neurons in normal and neuropathic conditions, J. Neurosci. 18 (1998) 2174–2187. [29] N. Ogata, H. Tatebayashi, Kinetic analysis of two types of Na 1 channels in rat dorsal root ganglia, J. Physiol. (Lond.) 466 (1993) 9–37. [30] M. Ohsawa, J. Kamei, Possible involvement of protein kinase C in the attenuation of DAMGO-induced antinociception in diabetic mice, Eur. J. Pharmacol. 339 (1997) 27–31. [31] M. Ohsawa, J. Kamei, Possible involvement of spinal protein kinase C in the thermal allodynia and hyperalgesia in diabetic mice, Eur. J. Pharmacol. 372 (1999) 221–228. [32] M. Ohsawa, T. Kashiwazaki, J. Kamei, Modulation of the formalininduced nociceptive response by diabetes: possible involvement of protein kinase C, Brain Res. 803 (1998) 198–203. [33] F. Porecca, J. Lai, D. Bian, S. Wegert, M.H. Ossipov, R.M. Eglen, L. Kassotakis, S. Novakovic, D. Rabert, L. Sangameswaran, J.A. Hunter, Comparison of the potential role of the tetrodotoxin-insensitive sodium channels, PN3 / SNS and NaN / SNS2, in rat model of chronic pain, Proc. Natl. Acad. Sci. USA 96 (1999) 7640–7644. [34] D.K. Rabert, B.D. Koch, M. Ilnicka, R.A. Obernolte, S.L. Naylor, R.C. Herman, R.M. Eglen, J.C. Hunter, L. Sangameswaran, A tetrodotoxin-resistant voltage-gated sodium channel from human dorsal root ganglia, hPN3 / SCN10A, Pain 78 (1998) 107–114. [35] A.M. Ritter, I.M. Mendell, Somal membrane properties of physiologically identified sensory neurons in the rat: effects of nerve growth factor, J. Neurophysiol. 68 (1992) 2033–2041. [36] L. Sangameswaran, S.G. Delgado, L.M. Fish, B.D. Koch, L.B. Jakeman, G.R. Stewart, P. Sze, J.C. Hunter, R.M. Eglen, R.C. Herman, Structure and function of a novel voltage-gated tetrodotoxin-resistant sodium channel specific to sensory neurons, J. Biol. Chem. 271 (1996) 5953–5956.
J. Kamei et al. / Brain Research 948 (2002) 17 – 23 [37] K. Schepelmann, K. Meßlinger, R.F. Schmidt, The effects of phorbol ester on slowly conducting afferents of the cat’s knee joint, Exp. Brain Res. 92 (1993) 391–398. [38] T. Shiba, T. Inoguchi, R. Sportsman, W. Health, S.E. Bursell, G.L. King, Correlation of diacylglycerol level and protein kinase C activity in rat retina to retinal circulation, Am. J. Physiol. 265 (1993) E787–E793. [39] M. Shibata, T. Ohkubo, H. Takahashi, R. Inoki, Modified formalin test: characteristic biphasic pain response, Pain 38 (1989) 347–352. [40] J.H. Song, K. Nagata, H. Tatebayashi, T. Narahashi, Interaction of tetramethrin, fenvalerate and DDT at the sodium channel in rat dorsal root ganglion neurons, Brain Res. 708 (1996) 29–37. [41] A.M. Strassman, S.A. Raymond, Electrophysiological evidence for tetrodotoxin-resistant sodium channels in slowly conducting dural sensory fibers, J. Neurophysiol. 81 (1999) 413–424. [42] A. Tanaka, Y. Kashiwagi, T. Ogawa, N. Abe, T. Asahina, M. Ikebuchi, Y. Takagi, Y. Shigeta, Effect of verapamil on cardiac protein kinase C activity in diabetic rats, Eur. J. Pharmacol. 200 (1991) 353–356.
23
[43] S. Tate, S. Benn, C. Hick, D. Trezise, V. John, R.J. Mannion, M. Costigan, C. Plumpton, D. Grose, Z. Gladwell, G. Kendall, K. Dale, C. Bountra, C.J. Woolf, Two sodium channels contribute to the TTX-R sodium current in primary sensory neurons, Nature Neurosci. 1 (1998) 653–655. [44] C.L. Thio, H. Sontheimer, Differential modulation of TTX-sensitive and TTX-resistant Na 1 channels in spinal cord astrocytes following activation of protein kinase C, J. Neurosci. 13 (1993) 4889–4897. [45] B.A. Wolf, J.R. Williamson, R.A. Easom, K. Chang, W.R. Sherman, J. Turk, Diacylglycerol accumulation and microvascular abnormalities induced by elevated glucose levels, J. Clin. Invest. 98 (1990) 31–38. [46] K. Yashpal, G.M. Pitcher, A. Parent, R. Quirion, T.J. Coderre, Noxious thermal and chemical stimulation induce increase in 3Hphorbol 12,13-dibutyrate binding in spinal cord dorsal horn as well as persistent pain and hyperalgesia, which is reduced by inhibition of protein kinase C, J. Neurosci. 15 (1995) 3263–3272. [47] S. Yoshida, Tetrodotoxin-resistant sodium channels, Cell Mol. Neurobiol. 14 (1994) 227–244.