P.l.c.042 Antihyperalgesic and antiallodynic effect of chronic lactoferrin administration in neuropathic pain

P.l.c.042 Antihyperalgesic and antiallodynic effect of chronic lactoferrin administration in neuropathic pain

P.l.c Basic and clinical neuroscience - Neuropharmacology is in 8-12 Hz bands. In postischemia-vinpocetine group, 4-8 Hz bands are decreased and slig...

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P.l.c Basic and clinical neuroscience - Neuropharmacology

is in 8-12 Hz bands. In postischemia-vinpocetine group, 4-8 Hz bands are decreased and slight increasing is detected in 12-18 Hz. In pre&post-vinpocetine group, there is no change is detected in frontal region but 12-18 Hz decreasing and 4-8 Hz increasing is detected in parietal-occipital regions. Decreasing of the 4-8 Hz bands in ischemia group is not changed in preischemia and postischemia-vinpocetin groups. However, this decreasing is prevented in pre&postischemia-vinpocetine group. Increasing of 12-18 Hz bands as seen in ischemia group is not detected in preischemia-vinpocetin group and it is detected slighty in postischemia-vinpocetin group. Conclusion: Preischemic treatment of vinpocetine is more neuroprotective than post ischemic treatment when they are compared with sham and ischemia groups. It is suggested continuous vinpocetine treatment is the most protective and therapeutic in I/R.

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Results: Our PCR studies demonstrate that these cells constitutively express IL-l receptor, IL-6 receptor and the signal transducing membrane protein gp130. Both IL-l~ and IL-6 showed an increase in the level of proliferation (8% increase for IL-l~ at 100 ng/ml, P < 0.001, and 7% increase for IL-6 at 125 ng/ml, P < 0.05), while higher concentrations resulted in cell death. We also detected expression of glucocorticoid receptor, mineralocorticoid receptor, the serotonin transporter SLC6A4 and the serotonin receptor HTRlA. A study on their regulation upon treatment with cytokines is currently under way. Conclusions: These data suggest that IL-6 and IL-l ~ have an impact on hippocampal cell proliferation. We are evaluating at present the effect of both cytokines on differentiation. Disclosure of interest: Professor Jack Price acted as a consultant and received payment from ReNeuron group within the last 2 years.

References [1] Bonoczk p, Pancze1 G, Nagy Z, Vinpocetine increases cerebral blood flow and oxygenation in stroke patients: a near infrared spectroscopy and transcranial Doppler study. European Journal of Ultrasound 15:85-91. [2] Bereczki D, Fekete I., 2000. Vinpocetine for acute ischeamic stroke. Cochrane Database Syst Rev.; (2):CD000480. Review.

References

1P.1.C.0411 The role of pro-inflammatory cytokines IL-111 and IL-6 on proliferation of human hippocampal neural stem cells

IP.1.c.0421 Antihyperalgesic and antiallodynic effect

P. Zunszain1 " C. Anacker1 , L. Carvalho 1 , S. Thuret1 , 1. Price 1 , C.M. Pariante 1 . 1Institute ofPsychiatry King's College London, Psychological Medicine, London, United Kingdom

A. Onal 1 , G. Kayalioglu2 , A. Parla?', A. K.eser4, S. Ulker1 . 1Ege University Faculty of Medicine, Department of Pharmacology and Clinical Pharmacology, Izmir, Turkey; 2 Ege University Faculty of Medicine, Department of Anatomy, Izmir, Turkey; 3 Manisa Mental Hospital, Toxicology and Drug Abuse, Manisa, Turkey; 4 Ege University Faculty of Medicine, Department ofPhysiology, Izmir, TUrkey

Purpose of the study: Recent developments in psychiatric research have led to the hypothesis that inflammatory processes may be involved in the pathogenesis of depression [1]. In particular, it has been repeatedly shown that some patients with depression have elevated plasma levels of pro-inflammatory mediators, including IL-l~, IL-2, IL-6 and C-reactive protein. Furthermore, several lines of evidence indicate that decreased neurogenesis may also be implicated in psychiatric disorders [2]. As the complete role of cytokines in both physiological and pathological conditions of neurogenesis is not known, we wanted to investigate the role of pro-inflammatory cytokines interleukin-6 (IL-6) and interleukin1beta (IL-l ~) on proliferation of human hippocampal cells. In addition, in order to analyse potential mechanisms by which cytokines can regulate neurogenesis and based on the notion that cytokines can cause glucocorticoid receptor resistance and can modulate monoamine neurotransmitters, we wanted to investigate whether relevant molecular targets (glucocorticoid and mineralocorticoid receptors, serotonin receptor and serotonin transporter) were present in our cells. Methods: We used a cmyc-ERTAM conditionally immortalized human multipotent hippocampal stem cell line (HPCOA07, ReNeuron Ltd, UK) as a model. In order to study proliferation, cells were incubated for 24 and 72 hours in the presence of IL-6 (0.25-250 ng/mL) and IL-l~ (0.1-500 ng/ml). Cell proliferation was assayed by Ki67 immunocytochemistry. The fraction of Ki67 positive cells over the total number of cells was determined by cell counting. PCR was used to detect expression of target gene transcripts, and primer sequences were determined using established human GeneBank sequences.

[1] Dantzer R, O'Connor JC, Freund GG, Johnson RW, Kelley KW. 2008 From inflammation to sickness and depression: when the immune system subjugates the brain. Nat Rev Neurosci. Jan;9(1 ):46-56 [2] Kempermann G, Krebs J, Fabel K. 2008 The contribution of failing adult hippocampal neurogenesis to psychiatric disorders. Curr Opin Psychiatry. May;21(3):290-5

of chronic lactoferrin administration in neuropathic pain

Purpose: Lactoferrin is found in milk, neutrophils and other biological fluids and contributes to immunomodulation, cell growth regulation and the induction of primary defense against infections. The anti-nociceptive effect of bovine milk lactoferrin (hLF) has been defined in various non-inflammatory pain models such as formalin, hot plate, acetic acid writhing and tail-flick tests; however the antihyperalgesic or antiallodynic effect ofbLF in inflammatory conditions that induce pain has not been well documented yet. Therefore, this study aimed to investigate the effect of bLF on hyperalgesia and allodynia in a rat model of neuropathic pain; the involvement of c-fos, TNF-a, nitric oxide and opioidergic systems in this effect was also studied. Methods: Neuropathic pain was induced in rats by loose ligation of the right sciatic nerve and evaluated using tests measuring the mechanical, termal hyperalgesia and allodynia. bLF (50, 100, 200mglkg) alone or in combination with opiodergic antagonists and L-NAME, 7-nitroindozole or L-canavanine alone were administered intraperitoneally to the rats with neuropathic pain. Immunocytochemistry for c-fos (as a marker of pain) and NADPH-d (as a marker ofnitric oxide synthase activity) and Western blotting for TNF-a, inducible (iNOS) and neuronal (nNOS) forms ofnitric oxide synthase were performed in the lumbar spinal cord of rats. Plasma TNF-a levels were determined with ELISA. Results: Acute, single dose bLF administration did not affect pain threshold in neuropathic rats; however, chronic administration

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P.l.c Basic and clinical neuroscience - Neuropharmacology

of bLF for 15 days produced antihyperalgesic and antiallodynic effects in neuropathic rats. Pretreatment of neuropathic rats with opiodergic antagonists before pain tests significantly decreased the antinociceptive effect ofbLF; indicating that bLF may act through the potentiation of endogenous opioid system. NOS inhibitors L-NAME and L-canavanine, but not 7-nitroindazole, produced antiallodynic effects in neuropathic rats. Induction of neuropathic pain resulted in a significant increase in iNOS and TNF-a protein expression in the L3-L4 segment ofrat medulla spinalis (P < 0.01); however, nNOS expression remained unchanged. The number of c-Fos- and NADPH-d-positive cells was increased in the medulla spinalis of neuropathic rats. Chronic bLF treatment decreased c-fos and NADPH-d immunoreactivity, as well as TNF-a and iNOS expression at 50 and 100 mg/kg; additionally, bLF administration at 100 mg/kg resulted in a further decrease of nNOS expression in the lumbar spinal cord of neuropathic rats. Plasma TNF-a levels remained unchanged after bLF treatment. Conclusion: Prolonged intraperitoneal administration of bLF exerts antihyperalgesic and antiallodynic effect in neuropathic rats. This effect is probably mediated by the down-regulation of iNOS and TNF-a protein expression in the lumbar spinal cord; potentiation of the endogenous opioid system by bLF may also contribute to bLF-induced antihyperalgesic and antiallodynic effect. It has been suggested that, with its structure differing from classical analgesics, repeated administration of LF may provide a natural drug alternative for the treatment of chronic pain conditions such as the neuropathic pain. *This study was supported by the National Young Researchers Career Development Programme (Career Programme) of TUBITAK (The Scientific and Technological Research Council of Turkey) (project no: 104S287). References [1] Farnaud S., Ewans Sw., 2003 Lactoferrin-a multifunctional protein with antimicrobial properties. Molecular Immunology, 40, 395--405. [2] Hayashida K., Takeuchi T., Shimizu H., Ando K., Harada E., 2003 Novel function of bovine milk-derived lactoferrin on antinociception mediated by rnii-opioid receptor in the rat spinal cord. Brain Research 965, 239-245. [3] Kayalioglu G., Balkan 8., 2004 Expression of c-Fos and NADPH-d after peripheral noxious stimulation in the pedunculopontine tegmental nucleus. Neuroreport, 15, 421--423.

IP.1.c.0431 ACR325: a dopaminergic stabiliser that displays state-dependent effects in-vivo H. Ponten 1 ., T. Dyhring2, M. Edling 1 , F. Pettersson1 , C. Sonesson1 , B. Svanberg 1 , L. Swanson1 , J. Tedrofl'l , S. Waters 1 , N. Waters 1 . 1NeuroSearch Sweden AB, Drug Discovery, Goteborg, Sweden; 2 NeuroSearch A/S, Drug Discovery, Ballerup, Denmark Purpose of study: A major clinical challenge in the treatment of neurological and psychiatric disorders is to improve long-term outcome with improved tolerability. Addressing the above we aim to develop new treatments, which target both dopaminergic and glutamatergic systems, for neurologic and psychiatric disorders. Methods: ACR325 has been characterized in vivo, in male Sprague-Dawley rats, measuring effect on locomotor activity, extracellular levels of monoaminiergic neurotransmitters, postmortem tissue monoaminergic neurochemistry and expression of lEG mRNA. In addition, receptor interaction studies of ACR325 in functional DA D2 in-vitro assays has been performed.

Results: In-vivo ACR325 exerts clear effects on rat brain monoaminergic systems, as manifested by e.g. dose dependent increases in extracellular levels of dopamine and noradrenaline, in particular in the frontal cortex, as well as increased brain tissue levels of dopamine metabolites in the basal ganglia, limbic areas and in the frontal cortex, (e.g. striatal DOPAC, ED50 = 48 I-lmol/kg s.c.). In-vitro ACR325 displays a fast-offDA D2 receptor kinetics profile. Furthermore, ACR325 increases levels ofmRNA encoding Arc (activity related cytoskeletal protein) in the frontal cortex and striatum, suggesting enhanced NMDA mediated glutamatergic neurotransmission in these areas. In addition, ACR325 acutely increases levels of mRNA encoding the neurotrophic peptide BDNF (brain derived nerve growth factor). Hyperactivity induced in different psychosis models is potently inhibited, ED50 is 37 I-lmol/kg s.c. in the d-amphetamine model and in the MK-801 model ED50 is 22 I-lmol/kg s.c. Yet, unlike marketed compounds which also interact with DA D2 receptors, ACR325 has minimal effects on locomotor activity in non-pretreated rats. Conclusions: The dopaminergic stabilizer ACR325 has state dependent behavioural effects, in that it suppress the hyperactive locomotor activity induced in animal models where dopamine or glutamate systems are stimulated or inhibited, respectively, but do not suppress locomotor activity under normal conditions. Neurochemical effects of ACR325 resemble those of dopamine D2 receptor antagonists, with increases in dopamine metabolites, and increased release of dopamine. The release of dopamine is especially pronounced in the frontal cortex and is followed by strengthening of prefrontal glutamatergic functions, suggesting beneficial effects also in cognitive symptom domains. In view of studies concluding that increased BDNF levels is an essential part of the brain processes leading to recovery from depression, a potential for ACR325 in the treatment of affective symtomatology is suggested. The unique pharmacological effects of ACR325 including stabilization of dopamine dependent behaviours and enhancement of cortico-striatal glutamate transmission suggest that neurological as well as psychiatric, especially psychotic symptoms can be treated. The lack of behavioural impact of ACR325 at doses where hyperactivity is reduced in models of increased dopamine or reduced glutamate transmission, indicates a favorable long-term tolerability in the clinical setting. Hence, the pre-clinical pharmacodynamic profile and apparent neurological safety of ACR325 predicts that the compound could be suitable for maintenance in neurology as well as psychiatry. Shares: The authors hold equity and/or options in NeuroSearch Paid positions: The authors are employed by NeuroSearch, that hold patents for ACR325

1P.1.c.0441 Paradoxical effects of GABA on the in vivo uptake of the partial inverse GABA agonist [3H]R015-4513 in rat brain R.J. Tyacke 1 ., E.S.J. Robinson2 , A Harris2 , AR. LingfordHughes 1 , D.J. Nutt1 . 1 University ofBristol, Psychopharmacology Unit, Bristol, United Kingdom; 2 University ofBristol, Department ofPhysiology and Pharmacology, Bristol, United Kingdom GABA is the major inhibitory neurotransmitter and so is involved in a wide range of disorders from anxiety to epilepsy and alcohol addiction. The study of the GABA system is therefore very important in understanding brain function and has been investigated using many neuroimaging techniques including PET.