Characterisation of the 5-HT receptor potentiating neurotransmission in rabbit bladder.
We have investigated the effects of 5-hydroxytryptamine (5-HT) on electrically induced contractions of rabbit isolated bladder. Electrical field stimulation evoked twitch contractions which were potentiated by 5-HT (0.3-10 microM). The potentiating effect of 5-HT was inhibited by ondansetron (pA2 9.2) and granisetron (pA2 9.1) but not by methysergide or SB 204070 ((1-butyl-4-piperidinyl)methyl 8-amino-7-chloro-1,4-benzodioxan-5-carboxylate hydrochloride). This suggests that the potentiating effect of micromolar concentrations of 5-HT on neuromuscular transmission in rabbit isolated bladder is mediated by 5-HT3 receptors. The receptors involved in the response to lower concentrations of 5-HT, observed in some tissues, remain to be characterised.
Barras
M
M
Synthélabo Recherche (L.E.R.S.), Department of Internal Medicine, Rueil Malmaison, France.
Van der Graaf
P H
PH
Angel
I
I
D008735:5-Methoxytryptamine / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D011817:Rabbits; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D009435:Synaptic Transmission; D001743:Urinary Bladder / Q000502:physiology*
D011985:Receptors, Serotonin; D012701:Serotonin; D008735:5-Methoxytryptamine