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Cyclic nucleotides and crustacean blood glucose levels
Comp. Blochem. Physiol., 1976, Vol. $4A, pp. 301 t~ 304. Perflanmn Press. Printed in Great Britain
CYCLIC N U C L E O T I D E S AND CRUSTACEAN B L O O D GLUCOSE LEVELS KLAUS-DIETER SPINDLER,t AXEL WILLIG2 AND RA1NER KELLER2 ZFachbereich Biologic-Zoologic der Technischen Hochschule, 61 Darmstadt, Germany; and 2Abteilung Biologic I der Universitiit, 79 Ulm, Germany (Received 9 October 1975) Ahstraet--l. The influence of cyclic nucleotides, theophyUine, NaF, 5'AMP, and adenine on the blood sugar level of Uca puoilator and Orconecees limosus was investigated. 2. In both species, cAMP increased blood glucose in intact animals whereas in eyestalkless animals, a slight but significant effect was observed only in Orconectes. The effect of cGMP, which has been tested in Orconectes only, was similar to that of cAMP. 3. 5'AMP and adenosine were found to be hyperglycemic in intact Uca but not in eyestalkless animals. 4. In Orconectes no hyperglycemic effect of sublethal doses of NaF was observed. Theophylline in high doses increased the blood glucose level. 5. The results indicate that the hyperglycemic effect of cyclic nucleotides is essentially due to an increased release of hyperglycemic hormone from the eyestalks rather than to a direct action on the glycogen-containing tissues.
INTRODUCTION The sinus gland in the eyestalks of decapod Crustacea is the storage a n d release site of a hyperglycemic n e u r o h o r m o n e (HGH) (Abramowitz et aL, 1944) whose isolation a n d characterization has been dealt with in several studies (Kleinholz et aL, 1967; Keller, 1968; Kleinholz & Keller, 1973). T o date, in investigations on the mechanisms responsible for the elevation of blood sugar only crude eyestalk extracts have been used. Eyestalk extract has been shown to activate phosphorylase and to inhibit glycogen synthetase in "muscle tissue (Keller, 1965, 1966; R a m a m u r t h i et aL, 1968). Phosphorylase activation can be elicited by 3',5'-adenosine monophosphate (cAMP) as has been demonstrated by Bauchau et aL (1968) in Eriocheir muscle. Accordingly, glycogenolysis i n abdominal muscle of Orconectes upon injection of eyestalk extract has been shown by Keller & Andrew (1973). Finally, in experiments on a b d o m i n a l muscle o f Cambarus robustus in vitro, NaF, a k n o w n activator of adenyl cyclase, was found to stimulate glucose release into the medium (Telford, 1975) a n d c A M P a n d 3',5'-guanosine monophosphate (cGMP) specific protein kinases have been previously identified in lobster abdominal muscle (Kuo et ai., 1971). These results suggest a second messenger-mechanism of horm o n a l l y s t i m u l a t e d glycogenolysis comparabl e to that o b s e r v e d in vertebrates. To obtain more information on this subject we examined the role of cyclic nucleotides in the induction of hyperglycemia in decapod Crustacea. MATERIALS AND M E T H O D S Intermolt male crayfish (Orconectes limosus, 19221 g)and fiddler crabs (Uea pugilator, 3 g) were used for the experiments and kept as previously described (Keller, 1969; Kleinholz & Keller, 1973). Orconectes were kept at 15°C, 301
Uca at 20-22°C. Eyestalks of Orconectes were removed 3 days, those of Uca I day before experiments. In experiments on Orconectes, substances were dissolved in Van Harreveld's solution (Van Harreveld, 1936) and 50 or 1(30 /.d injected into the pericardial cavity or through the joint membrane of a chela. In experi/nents on Uca, substances were dissolved in Pantin's saline.(Pantin, 1934) and 5 ~ injected through the coxal membrane of a walking leg. All experiments were carried out at the same time of the day in order to eliminate circadian variations of the blood sugar level (Hamann, 1974). At the indicated times blood samples (50 or 100 ~ from Orconectes, 50 tA from Uca) were taken with calibrated siliconized glass capillaries. Double blood glucose determinations were carried out as described earlier (Kleinholz & Keller, 1973), employing glucose test kits (Worthington Glueostat and Boehringer GOD-Perid method). Dibutyryl derivatives of cAMP and cGMP were purchased from Boehringer GmbH, Mannheim. RESULTS Injection of c A M P increases the blood glucose levels in both Uca (Table 1 a n d Fig. 1) and Orconectes (Fig. 2). Similar results were obtained with c G M P in Orconectes (Fig. 3), I n crayfish the increase continues for 4 hr whereas in Uca a m a x i m u m is found 90 m i n after injection a n d the n o r m a l level is restored after 3 hr. I n Uca the time course of blood glucose after injection of c A M P differs from that o b t a i n e d after injection of eyestalk extracts o f Uca (Keller & Andrew, 1973). I n Orconectes a h3~erglycemic reaction was obtained after injection of a large dose of theophylline (Fig. 4), a k n o w n inhibitor of cyclic nucleotide phosphodiesterase. T h e increase of blood glucose level in Orconectes after injection o f the indicated a m o u n t s of cyclic nucleotides and theophylline is lower than the hyperglycemic effect after injection of eyestalk extracts equivalent to about 3 x 10 -2 eyestalks per animal. Injection of 2 / a n o l e p e r animal
302
K.-D.
SPINDLI'R,
A.
WILLIG
AND
R.
KELLER
fO0
2'
BO
_86o Ua
E
40
20
i! °*"°'"'" ~
"........................................................ i{i
=
S
Hr Fig. I. Hemolymph glucose in Uca puoilator after injection of 0.65 /~mole/g live wt of cAMP (11,[:]), 5'AMP (4l,, <>), adenosine (&,A), and adenine (O), Filled symbols: intact animals, unfilled symbols: eyestalkless animals. N = 5, means 4- l S.E.M.
Hr Fig. 3. Hemolymph glucose in Orconectes limosus after injection of dibutyryl c G M P into intact (filled symbols) and eyestalkless animals (unfilled symbols): 0.14 /lmole/g live wt (II, Q), I #mole/g live wt (A), controls (O,O). N = 6. means ± l S,E.M. Differences between experimental animals and controls are statistically signiticant (P <0,05) at 1, 2, and 4 hr after injection.
5(:
4C
_8 e.,
~K
E
fO
. . . . . . . . .a. .
~
l
a~
Hr
Fig. 2. Hemolymph glucose in Orconectes4imosus after:injection of dibutyryl cAMP i n t o intact (filled s y m b o l s ) a n d eyestalkless animals (unfilled symbols); I /~mole/g live wt (m, rq),:controls (O,O). N = 15, means 4- 1. S.E.M. Differences bdtwecn experimental a n i m a l s and controls a r e statistically significant (P <0.01) at i , 2 , 1 a n d 4 hr after injection.
0
• ,,,
~
!
2
/
"
• & T
Hr
Fig. 4. Hemolymph glucose in intact Orconectes limosus after injection :of: 0.25/m~ole:(s) and :L25 llmole (A) of theophylline; controls (0). N = 5, means 4- I S.E.M. Differences ibetween experimental animals and ~controls are statistieal!y Significant (P <0.05) at: 1, 2, and 4 hr' after injection.
Cyclic nucleotides Table 1. Hemolymph glucose in Uca pugilator 90 min after injection of increasing doses of cAMP Dose
n
moXe/animal oontz'ols* 5 x 10 " 1 0 3 x 10 - 9 3 x 10 . 8 3 x 10 - 7 5 x 10 -6
11 5
3 3
5 3
Hemolymph g l u o o s e mg/lO0 ml SEN 11.6 6.0 4.3 3,0 13.8 92.0
4.9 2.1 1.3 2.4 10.5 55.0
~In~eoted wl%h ]Pant£n~s sallne
of N a F into eyestalkless Orconectes did not increase the blood glucose level. Higher doses were lethal. Equimolar amounts (0.65 lLmole/g live wt) o f wlrious adenine derivatives revealed the following sucession of hyperglycemic effectiveness in intact Uca: c A M P > 5 ' A M P > adenosine > adenine. The last did not produce significant differences as compared to the controls. The adenine derivatives had no hyperglycemic effects in eyestalkless Uca (Fig. 1), whereas in eyestalkless Orconectes c A M P and c G M P caused a low but significant increase of the blood sugar level as compared to. eyestalkless controls (Figs. 1 & 2). c G M P appears to be more effective than c A M P (Figs. 2 & 3). The increase of the blood sugar level in intact Orconectes controls is obviously due to a release of H G H which is caused by the stress produced by the injection of saline a n d repeated taking of blood samples. Correspondingly, in eyestalkless controls no increase is observed. DISCUSSION Cyclic nucleotides and theophylline cause a hyperglycemic reaction in both species of decapod Crustacea. Nevertheless, c A M P and c G M P do not seem to be mediators of H G H action since (a) large doses are necessary to produce a hyperglycemic effect, (b) other adenine derivatives are also effective, and (c) the cyclic nucleotides produced a much lower reaction in eyestalkless animals than in intact ones. This is p r o b a b l y not caused by unspecific traumatic effects due to stirpation of the eyestalks because eyestalkless animals respond to injections o f eyestalk extract in the same way as intact animals. Attempts to demonstrate a stimulation of a d e n y l a t e cyclase in muscle after injection ofeyestalk extract did not succeed. The results rather suggest that cAMP, c G M P , the adenine derivatives, and theophylline cause a release of H G H from the sinus gland in the eyestalk. I n vertebrates t h e stimulation o f the release o f glneagon and insulin by c A M P was recently demonstrated (Jarrousse & Rosselin, 1974). A stimulation of H G H release was also discussed for the action o f serotonin in Orconectes (Keller & Beyer, 1968 ). In Orconectes a direct examination of this. hypothesis by determination of H G H content in the eyestalks of untreated animals and those whicla had been injected with cyclic nucleotides does n o t seem to be feasible since injection o f only 3-5 × 10-2 eyestalk equivalents produces a hyperglycemic response higher than the
303
responses observed. Probably, there are additional
direct effects of the cyclic nucleotides in the glycogen containing tissues which account for the low but statistically significant hyperglycemic reactions in eyestalkless Orconeetes. These effects may also account for the stimulation o f muscle phosphorylase by c A M P in Eriocheir which was demonstrated by Bauchau et al. (1968). The physiological significance of the stimulation o f H G H release by cyclic nucleotides, adenine derivatives, and theophylline remains obscure. Acknowledeements--Part of this study was carried out in the laboratory of Professor L. H. Kleinholz at Reed College, Portland, Ore. with support by grants NS 02606 fron NIH and 6B 31305X from NSF to L. H. K. K.-D. S. received further support from the Deutsche Forsehungsgemeinschaft and the Dcutscher Akademischer Austauschdienst. A. W. and R. K. were funded by the Deutsche ForschungsgemeinschaR (SFB 87, Ulm, Projekt A3).
REFERENCES ABRAMOWnrZ A. A., HISAW F. L. & P^PANDREA D. N. (1944) The occurence of a diabetogenic factor in the eyestalk of crustaceans. Biol. Bull. mar. biol. Lab., Woods Hole 86, 1-5.
BAUCrmU A. G., MENGEOT J. (2. & OLIvmg M. A. (1968) Action de la s6rotonine et de rhormone diab6tog6ne des crustacds sur la phosphorylase musculaire. Gen. scrap. Endocr. i l . 132-138. HAMANN A. (1974) Die neuroendokrine Steuerung tagesrhythmischer Blutzuckerschwankungen dutch die Sinusdriise beim FluBkrcbs. 3. scrap. PhysioL 89, 197-214. JARROUSSEC. ~ ROSSELING. (1975) Interaction of amino acids and cyclic AMP on the release of insulin and glucagon by newborn rat pancreas. Endocrinology 96. 168-177. KELLER R. (1965) Uber sine hormonale Kontrolle des Polysaccharid-Stoffwechscls beim FluBkrebs Cambarus affinis Say. Z. ver.oL Physiol. 51, 49-59. KELLER R. (1966) Uber sine hormonale Regulation der Glykogen-Synthese beim FluBkrebs Orconectes limosus Rafinesque (Cambarus affinis Say). Verh. Zool. Ges. Gbttingen, pp. 272-279. KELLER R. (1968) Ubcr Versuch zur Charakterisierung des diabctogenen Augenstielhormons des FluBkrebscs Orconectes limosus. Verb. Zool. Ges. lnnsbruck, pp. 628-635. KELLER R. (1969) Untersuchungen zur Artspezifit~t eines Crustaceenhormons. Z. vergl. Physiol. 63. 137-145. KELLER R. & BI':YERJ. 0968) Zur hyperglykiimischen Wirkung yon Serotonin und Augenstielextrakt beim Flulgkrebs Oreonectes limosus. Z. vergi. PhysioL 59, 78-85. KELLER R. & ANDREW E. M. (1973) The site of action of the crustacean hyperglycemic hormone. Gen. comp. Endocr. 20. 572-578. KLEINHOLZ L. H., KIMBALLF. & MCGARVEY M. (1967) Initial characterization and separation of hyperglycemic (diabetogenic) hormone from the crustacean eyestalk. Gen. comp. Endocr. 8. 75-81. KLEINHOLZL. H. & KELLERR. (1973) Comparative studies in crustacean neurosccretory hyperglycemic hormones. I. The initial survery. Gen. comp. Endocr. 21, 554-564. KUo J. F., WvA'rr G. R. & GREENGARD P. (1971) Cyclic nucleotide-dependent protein kinases. IX. Partial purification and some properties of guanosine 3',5'-monophosphate-dependent an~ adenosine 3',5'-monophosphate-dependent protein kinases from various tissues and species of Arthropoda, J. biol. Chem. 246, 7159-7167.
304
K.-D. St'tN~LER,A. WILLIGAND R. KELLER
P^NTIN C, F. A. (1934) On the excitation of the crustacean muscle. J. exp. Biol, ! I, 11-27. R^m^mu~'rm R,, MUMaACHM, W. & SCH~R B. T. (1968) Endocrine control of glycogen synthesis in crabs. Comp. Blochem. Physiol. 26. 311-319. TELFORI> M. (1975) Blood glucose in crayfish--IIL The
source of glucose and role of the eyestalk factor in hyperglycemia of Cambarus robustus. Comp, Biochem, Physiol, 51B, 69-73. VAN H^rrEVELD A. 0936) A physiological solution for freshwater crustaceans. Proc. Soc. exp. Biol. U.S. 34, 428-432.
CYCLIC N U C L E O T I D E S AND CRUSTACEAN B L O O D GLUCOSE LEVELS KLAUS-DIETER SPINDLER,t AXEL WILLIG2 AND RA1NER KELLER2 ZFachbereich Biologic-Zoologic der Technischen Hochschule, 61 Darmstadt, Germany; and 2Abteilung Biologic I der Universitiit, 79 Ulm, Germany (Received 9 October 1975) Ahstraet--l. The influence of cyclic nucleotides, theophyUine, NaF, 5'AMP, and adenine on the blood sugar level of Uca puoilator and Orconecees limosus was investigated. 2. In both species, cAMP increased blood glucose in intact animals whereas in eyestalkless animals, a slight but significant effect was observed only in Orconectes. The effect of cGMP, which has been tested in Orconectes only, was similar to that of cAMP. 3. 5'AMP and adenosine were found to be hyperglycemic in intact Uca but not in eyestalkless animals. 4. In Orconectes no hyperglycemic effect of sublethal doses of NaF was observed. Theophylline in high doses increased the blood glucose level. 5. The results indicate that the hyperglycemic effect of cyclic nucleotides is essentially due to an increased release of hyperglycemic hormone from the eyestalks rather than to a direct action on the glycogen-containing tissues.
INTRODUCTION The sinus gland in the eyestalks of decapod Crustacea is the storage a n d release site of a hyperglycemic n e u r o h o r m o n e (HGH) (Abramowitz et aL, 1944) whose isolation a n d characterization has been dealt with in several studies (Kleinholz et aL, 1967; Keller, 1968; Kleinholz & Keller, 1973). T o date, in investigations on the mechanisms responsible for the elevation of blood sugar only crude eyestalk extracts have been used. Eyestalk extract has been shown to activate phosphorylase and to inhibit glycogen synthetase in "muscle tissue (Keller, 1965, 1966; R a m a m u r t h i et aL, 1968). Phosphorylase activation can be elicited by 3',5'-adenosine monophosphate (cAMP) as has been demonstrated by Bauchau et aL (1968) in Eriocheir muscle. Accordingly, glycogenolysis i n abdominal muscle of Orconectes upon injection of eyestalk extract has been shown by Keller & Andrew (1973). Finally, in experiments on a b d o m i n a l muscle o f Cambarus robustus in vitro, NaF, a k n o w n activator of adenyl cyclase, was found to stimulate glucose release into the medium (Telford, 1975) a n d c A M P a n d 3',5'-guanosine monophosphate (cGMP) specific protein kinases have been previously identified in lobster abdominal muscle (Kuo et ai., 1971). These results suggest a second messenger-mechanism of horm o n a l l y s t i m u l a t e d glycogenolysis comparabl e to that o b s e r v e d in vertebrates. To obtain more information on this subject we examined the role of cyclic nucleotides in the induction of hyperglycemia in decapod Crustacea. MATERIALS AND M E T H O D S Intermolt male crayfish (Orconectes limosus, 19221 g)and fiddler crabs (Uea pugilator, 3 g) were used for the experiments and kept as previously described (Keller, 1969; Kleinholz & Keller, 1973). Orconectes were kept at 15°C, 301
Uca at 20-22°C. Eyestalks of Orconectes were removed 3 days, those of Uca I day before experiments. In experiments on Orconectes, substances were dissolved in Van Harreveld's solution (Van Harreveld, 1936) and 50 or 1(30 /.d injected into the pericardial cavity or through the joint membrane of a chela. In experi/nents on Uca, substances were dissolved in Pantin's saline.(Pantin, 1934) and 5 ~ injected through the coxal membrane of a walking leg. All experiments were carried out at the same time of the day in order to eliminate circadian variations of the blood sugar level (Hamann, 1974). At the indicated times blood samples (50 or 100 ~ from Orconectes, 50 tA from Uca) were taken with calibrated siliconized glass capillaries. Double blood glucose determinations were carried out as described earlier (Kleinholz & Keller, 1973), employing glucose test kits (Worthington Glueostat and Boehringer GOD-Perid method). Dibutyryl derivatives of cAMP and cGMP were purchased from Boehringer GmbH, Mannheim. RESULTS Injection of c A M P increases the blood glucose levels in both Uca (Table 1 a n d Fig. 1) and Orconectes (Fig. 2). Similar results were obtained with c G M P in Orconectes (Fig. 3), I n crayfish the increase continues for 4 hr whereas in Uca a m a x i m u m is found 90 m i n after injection a n d the n o r m a l level is restored after 3 hr. I n Uca the time course of blood glucose after injection of c A M P differs from that o b t a i n e d after injection of eyestalk extracts o f Uca (Keller & Andrew, 1973). I n Orconectes a h3~erglycemic reaction was obtained after injection of a large dose of theophylline (Fig. 4), a k n o w n inhibitor of cyclic nucleotide phosphodiesterase. T h e increase of blood glucose level in Orconectes after injection o f the indicated a m o u n t s of cyclic nucleotides and theophylline is lower than the hyperglycemic effect after injection of eyestalk extracts equivalent to about 3 x 10 -2 eyestalks per animal. Injection of 2 / a n o l e p e r animal
302
K.-D.
SPINDLI'R,
A.
WILLIG
AND
R.
KELLER
fO0
2'
BO
_86o Ua
E
40
20
i! °*"°'"'" ~
"........................................................ i{i
=
S
Hr Fig. I. Hemolymph glucose in Uca puoilator after injection of 0.65 /~mole/g live wt of cAMP (11,[:]), 5'AMP (4l,, <>), adenosine (&,A), and adenine (O), Filled symbols: intact animals, unfilled symbols: eyestalkless animals. N = 5, means 4- l S.E.M.
Hr Fig. 3. Hemolymph glucose in Orconectes limosus after injection of dibutyryl c G M P into intact (filled symbols) and eyestalkless animals (unfilled symbols): 0.14 /lmole/g live wt (II, Q), I #mole/g live wt (A), controls (O,O). N = 6. means ± l S,E.M. Differences between experimental animals and controls are statistically signiticant (P <0,05) at 1, 2, and 4 hr after injection.
5(:
4C
_8 e.,
~K
E
fO
. . . . . . . . .a. .
~
l
a~
Hr
Fig. 2. Hemolymph glucose in Orconectes4imosus after:injection of dibutyryl cAMP i n t o intact (filled s y m b o l s ) a n d eyestalkless animals (unfilled symbols); I /~mole/g live wt (m, rq),:controls (O,O). N = 15, means 4- 1. S.E.M. Differences bdtwecn experimental a n i m a l s and controls a r e statistically significant (P <0.01) at i , 2 , 1 a n d 4 hr after injection.
0
• ,,,
~
!
2
/
"
• & T
Hr
Fig. 4. Hemolymph glucose in intact Orconectes limosus after injection :of: 0.25/m~ole:(s) and :L25 llmole (A) of theophylline; controls (0). N = 5, means 4- I S.E.M. Differences ibetween experimental animals and ~controls are statistieal!y Significant (P <0.05) at: 1, 2, and 4 hr' after injection.
Cyclic nucleotides Table 1. Hemolymph glucose in Uca pugilator 90 min after injection of increasing doses of cAMP Dose
n
moXe/animal oontz'ols* 5 x 10 " 1 0 3 x 10 - 9 3 x 10 . 8 3 x 10 - 7 5 x 10 -6
11 5
3 3
5 3
Hemolymph g l u o o s e mg/lO0 ml SEN 11.6 6.0 4.3 3,0 13.8 92.0
4.9 2.1 1.3 2.4 10.5 55.0
~In~eoted wl%h ]Pant£n~s sallne
of N a F into eyestalkless Orconectes did not increase the blood glucose level. Higher doses were lethal. Equimolar amounts (0.65 lLmole/g live wt) o f wlrious adenine derivatives revealed the following sucession of hyperglycemic effectiveness in intact Uca: c A M P > 5 ' A M P > adenosine > adenine. The last did not produce significant differences as compared to the controls. The adenine derivatives had no hyperglycemic effects in eyestalkless Uca (Fig. 1), whereas in eyestalkless Orconectes c A M P and c G M P caused a low but significant increase of the blood sugar level as compared to. eyestalkless controls (Figs. 1 & 2). c G M P appears to be more effective than c A M P (Figs. 2 & 3). The increase of the blood sugar level in intact Orconectes controls is obviously due to a release of H G H which is caused by the stress produced by the injection of saline a n d repeated taking of blood samples. Correspondingly, in eyestalkless controls no increase is observed. DISCUSSION Cyclic nucleotides and theophylline cause a hyperglycemic reaction in both species of decapod Crustacea. Nevertheless, c A M P and c G M P do not seem to be mediators of H G H action since (a) large doses are necessary to produce a hyperglycemic effect, (b) other adenine derivatives are also effective, and (c) the cyclic nucleotides produced a much lower reaction in eyestalkless animals than in intact ones. This is p r o b a b l y not caused by unspecific traumatic effects due to stirpation of the eyestalks because eyestalkless animals respond to injections o f eyestalk extract in the same way as intact animals. Attempts to demonstrate a stimulation of a d e n y l a t e cyclase in muscle after injection ofeyestalk extract did not succeed. The results rather suggest that cAMP, c G M P , the adenine derivatives, and theophylline cause a release of H G H from the sinus gland in the eyestalk. I n vertebrates t h e stimulation o f the release o f glneagon and insulin by c A M P was recently demonstrated (Jarrousse & Rosselin, 1974). A stimulation of H G H release was also discussed for the action o f serotonin in Orconectes (Keller & Beyer, 1968 ). In Orconectes a direct examination of this. hypothesis by determination of H G H content in the eyestalks of untreated animals and those whicla had been injected with cyclic nucleotides does n o t seem to be feasible since injection o f only 3-5 × 10-2 eyestalk equivalents produces a hyperglycemic response higher than the
303
responses observed. Probably, there are additional
direct effects of the cyclic nucleotides in the glycogen containing tissues which account for the low but statistically significant hyperglycemic reactions in eyestalkless Orconeetes. These effects may also account for the stimulation o f muscle phosphorylase by c A M P in Eriocheir which was demonstrated by Bauchau et al. (1968). The physiological significance of the stimulation o f H G H release by cyclic nucleotides, adenine derivatives, and theophylline remains obscure. Acknowledeements--Part of this study was carried out in the laboratory of Professor L. H. Kleinholz at Reed College, Portland, Ore. with support by grants NS 02606 fron NIH and 6B 31305X from NSF to L. H. K. K.-D. S. received further support from the Deutsche Forsehungsgemeinschaft and the Dcutscher Akademischer Austauschdienst. A. W. and R. K. were funded by the Deutsche ForschungsgemeinschaR (SFB 87, Ulm, Projekt A3).
REFERENCES ABRAMOWnrZ A. A., HISAW F. L. & P^PANDREA D. N. (1944) The occurence of a diabetogenic factor in the eyestalk of crustaceans. Biol. Bull. mar. biol. Lab., Woods Hole 86, 1-5.
BAUCrmU A. G., MENGEOT J. (2. & OLIvmg M. A. (1968) Action de la s6rotonine et de rhormone diab6tog6ne des crustacds sur la phosphorylase musculaire. Gen. scrap. Endocr. i l . 132-138. HAMANN A. (1974) Die neuroendokrine Steuerung tagesrhythmischer Blutzuckerschwankungen dutch die Sinusdriise beim FluBkrcbs. 3. scrap. PhysioL 89, 197-214. JARROUSSEC. ~ ROSSELING. (1975) Interaction of amino acids and cyclic AMP on the release of insulin and glucagon by newborn rat pancreas. Endocrinology 96. 168-177. KELLER R. (1965) Uber sine hormonale Kontrolle des Polysaccharid-Stoffwechscls beim FluBkrebs Cambarus affinis Say. Z. ver.oL Physiol. 51, 49-59. KELLER R. (1966) Uber sine hormonale Regulation der Glykogen-Synthese beim FluBkrebs Orconectes limosus Rafinesque (Cambarus affinis Say). Verh. Zool. Ges. Gbttingen, pp. 272-279. KELLER R. (1968) Ubcr Versuch zur Charakterisierung des diabctogenen Augenstielhormons des FluBkrebscs Orconectes limosus. Verb. Zool. Ges. lnnsbruck, pp. 628-635. KELLER R. (1969) Untersuchungen zur Artspezifit~t eines Crustaceenhormons. Z. vergl. Physiol. 63. 137-145. KELLER R. & BI':YERJ. 0968) Zur hyperglykiimischen Wirkung yon Serotonin und Augenstielextrakt beim Flulgkrebs Oreonectes limosus. Z. vergi. PhysioL 59, 78-85. KELLER R. & ANDREW E. M. (1973) The site of action of the crustacean hyperglycemic hormone. Gen. comp. Endocr. 20. 572-578. KLEINHOLZ L. H., KIMBALLF. & MCGARVEY M. (1967) Initial characterization and separation of hyperglycemic (diabetogenic) hormone from the crustacean eyestalk. Gen. comp. Endocr. 8. 75-81. KLEINHOLZL. H. & KELLERR. (1973) Comparative studies in crustacean neurosccretory hyperglycemic hormones. I. The initial survery. Gen. comp. Endocr. 21, 554-564. KUo J. F., WvA'rr G. R. & GREENGARD P. (1971) Cyclic nucleotide-dependent protein kinases. IX. Partial purification and some properties of guanosine 3',5'-monophosphate-dependent an~ adenosine 3',5'-monophosphate-dependent protein kinases from various tissues and species of Arthropoda, J. biol. Chem. 246, 7159-7167.
304
K.-D. St'tN~LER,A. WILLIGAND R. KELLER
P^NTIN C, F. A. (1934) On the excitation of the crustacean muscle. J. exp. Biol, ! I, 11-27. R^m^mu~'rm R,, MUMaACHM, W. & SCH~R B. T. (1968) Endocrine control of glycogen synthesis in crabs. Comp. Blochem. Physiol. 26. 311-319. TELFORI> M. (1975) Blood glucose in crayfish--IIL The
source of glucose and role of the eyestalk factor in hyperglycemia of Cambarus robustus. Comp, Biochem, Physiol, 51B, 69-73. VAN H^rrEVELD A. 0936) A physiological solution for freshwater crustaceans. Proc. Soc. exp. Biol. U.S. 34, 428-432.