Evidence for the involvement of nitric oxide in the inhibitory effect of GSPYFVamide on Helix aspersa central neurones.
Intracellular recordings were made from neurones E-8, E-16 and E-13a in the visceral ganglion of Helix aspersa. GSPYFVamide inhibits the activity of these neurones and the role of a second messenger system in this inhibition was investigated. 8-Bromo-cGMP, 100 microM was found to potentiate this inhibition while ODQ, 100 microM, an inhibitor of guanylyl cyclase, almost completely blocked GSPYFVamide-induced inhibition. Four NO donors sodium nitroprusside, 100 microM, sodium nitrite, 1 mM, SNOG, 50 microM, and SNAP, 10-50 microM, all potentiated the GSPYFVamide-induced inhibition. L-NAME, 100-1000 microM, a competitive inhibitor of NOS, blocked the GSPYFVamide-induced inhibition. In some cases recovery was only partial. The possible role of NO in modulating the inhibitory response to GSPYFVamide is discussed.
Department of Physiology and Pharmacology, School of Biological Sciences, Bassett Crescent East, University of Southampton, UK.
S M
SM
Pedder
Y
Y
Muneoka
R J
RJ
Walker
D000818:Animals; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D006372:Helix, Snails; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology; D009603:Nitroso Compounds / Q000494:pharmacology; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology*; D010069:Oxadiazoles / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D026422:S-Nitrosoglutathione; D012977:Sodium Nitrite / Q000494:pharmacology
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D009603:Nitroso Compounds; D009842:Oligopeptides; D010069:Oxadiazoles; D011810:Quinoxalines; C110881:S-nitro-N-acetylpenicillamine; D009599:Nitroprusside; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D005978:Glutathione; D010396:Penicillamine; D006152:Cyclic GMP; D012977:Sodium Nitrite; D019331:NG-Nitroarginine Methyl Ester