Myenteric ganglionic 5-hydroxytryptamine(1P) signal transmission is mediated via Go protein.
The role of G proteins in mediating the signal transduction of the guinea pig myenteric ganglionic 5-hydroxytryptamine (5-HT)1P receptors was examined. Stimulation of ganglionic membranes with 5-HT in the presence of [35S]GTPgammaS or [alpha 32P]GTP increased guanine nucleotide binding to G(alpha)o but not to G(alpha)s, G(alpha)i or G(alpha)q in a concentration-dependent fashion. Pertussis toxin pretreatment markedly reduce this 5-HT induced response. Similarly, the 5-HT1P receptor-mediated slowly developing and long-lasting depolarizing response is potentiated by GTPgammaS and is inhibited by GDPbetaS or pertussis toxin. The activation of G(alpha)o by 5-HT also was mimicked by the 5-HT1P agonist, 5-hydroxyindalpine and was blocked by the selective 5-HT1P antagonist, N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide. These data provide compelling evidence to suggest that transmembrane signaling for the 5-HT1P receptors in isolated myenteric ganglia is transduced by the trimeric Go protein.
Wang
H Y
HY
Department of Pharmacology, Medical College of Pennsylvania and Hahnemann University, Philadelphia, USA.
Fiorica-Howells
E
E
Pan
H
H
Gershon
M D
MD
Friedman
E
E
D000818:Animals; D019204:GTP-Binding Proteins / Q000502:physiology*; D005724:Ganglia / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009197:Myenteric Plexus / Q000502:physiology*; D011817:Rabbits; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D015398:Signal Transduction
D011985:Receptors, Serotonin; D012701:Serotonin; D019204:GTP-Binding Proteins