Sulmazole effects on PGE2 and D-Ala2-Met-enkephalinamide modulation of cyclic AMP synthesis and neurotransmitter release in a sympathetic ganglion.
In the guinea-pig superior cervical ganglion, the Gi blocking agent sulmazole enhanced the basal and prostaglandin E2-induced stimulation of cyclic AMP synthesis but had no effect on the prostaglandin-dependent inhibition of acetylcholine release. On the contrary sulmazole counteracted the inhibitory effect of D-Ala2-Met-enkephalinamide both on cyclic AMP formation and acetylcholine release. Moreover sulmazole eliminated the supra-additive effect of the combination of prostaglandin + opiate on cyclic AMP synthesis. The presence of a Gi-coupled opiate receptor at the pre-and postsynaptic levels is suggested.
Institute of General Physiology, University of Ferrara, Italy.
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PG
Borasio
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Cervellati
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Fabbri
D000109:Acetylcholine / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D000242:Cyclic AMP / Q000096:biosynthesis*; D015232:Dinoprostone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D018377:Neurotransmitter Agents / Q000378:metabolism*
D002316:Cardiotonic Agents; D007093:Imidazoles; D018377:Neurotransmitter Agents; D004744:Enkephalin, Methionine; C022118:enkephalinamide-Met, Ala(2)-; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; C029758:sulmazole; D015232:Dinoprostone; D000109:Acetylcholine