5-HT1P receptor-mediated slow depolarization in neurons of guinea pig inferior mesenteric ganglion.

AIM

To study the effects of several 5-hydroxytryptamine (5-HT) receptor subtype antagonists on 5-HT-induced depolarization and the effects of 5-HT1P receptor agonist on the membrane potential in the neurons of guinea pig inferior mesenteric ganglion (IMG).

METHODS

Intracellular recordings were made from neurons of the isolated guinea pig IMG.

RESULTS

Cyproheptadine (5-HT1/2 antagonist 10 mumol.L-1, n = 7) and BRL 24924 (5-HT1P antagonist 10 mumol.L-1, n = 19) reversibly suppressed 5-HT slow response; pressure ejection of MCPP (5-HT1P agonist 10 mmol.L-1) induced a slow depolarization in most of 5-HT sensitive neurons (10/14).

CONCLUSION

5-HT-induced slow depolarization is mediated by 5-HT1P receptor.