Stimulation of formation of cAMP by 5-hydroxytryptamine in myenteric ganglia isolated from guinea pig small intestine.
Effects of 5-hydroxytryptamine (5-HT) and related agonists and antagonists on formation of cAMP were determined for enzymatically dissociated ganglia from the myenteric plexus of the guinea-pig small intestine. Formation of cAMP was stimulated by 5-HT in both dose- and time- dependent manners. The stimulatory action of 5-HT was suppressed by the 5-HT1P antagonist, renzapride, but not by the 5-HT3 antagonist, tropisetron (formerly ICS 205-930). Neither renzapride nor cisapride increased the levels of cAMP. Levels of cAMP were suppressed by concentrations of tropisetron greater than 1.0 microM. Levels of cAMP were unaffected by the 5-HT3 agonist, 2-methyl-5-hydroxytryptamine. A putative 5-HT4 receptor agonist, 5-methoxytryptamine, stimulated formation of cAMP, but to a lesser extent than 5-HT. We conclude that 5-HT acts to stimulate adenylate cyclase and the formation of cAMP in myenteric ganglia. The 5-HT1P receptor is the most likely subtype involved in 5-HT action on cAMP formation.
Xia
Y
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Department of Physiology, College of Medicine, Ohio State University Columbus 43210.
Fertel
R H
RH
Wood
J D
JD
D008735:5-Methoxytryptamine / Q000494:pharmacology; D000818:Animals; D020117:Cisapride; D000242:Cyclic AMP / Q000096:biosynthesis*; D005724:Ganglia / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000294:innervation*; D007700:Kinetics; D008297:Male; D009197:Myenteric Plexus / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D010880:Piperidines / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013268:Stimulation, Chemical; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
D010880:Piperidines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D008735:5-Methoxytryptamine; D013779:Tetrodotoxin; D000242:Cyclic AMP; D020117:Cisapride