Open AccessInteraction of 5-Hydroxytryptamine and Ketanserin in Rat Vas Deferens Subjected to Low Frequency Field Stimulation
Author(s) -
Akira Karasawa,
Kazuhiro Kubo,
Katsuichi Shuto,
Nobuhiro Nakamizo
Publication year - 1985
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.37.285
Subject(s) - ketanserin , methysergide , vas deferens , prazosin , medicine , endocrinology , chemistry , stimulation , phentolamine , inhibitory postsynaptic potential , 5 ht receptor , atropine , excitatory postsynaptic potential , propranolol , serotonin , receptor , antagonist
The interaction of 5-hydroxytryptamine (5HT) and ketanserin was investigated in isolated rat vas deferens. Ketanserin (10(-7) M) almost completely abolished the phasic and the following rhythmic contractions induced by 5HT, whereas the inhibition by prazosin (10(-6) M) or methysergide (10(-6) M) of 5HT-induced contractions were incomplete. The amplitude of twitch contractions of vas deferens subjected to low frequency (0.1 Hz) field stimulation were substantially unchanged by 5HT (10(-7)-10(-5) M) per se. After pretreatment of the tissue with ketanserin (10(-8)-10(-6) M), 5HT, in a concentration-dependent manner, attenuated the amplitude of twitch contractions. Such attenuation of the amplitude was not observed after pretreatments with methysergide (10(-8)-10(-6) M) or prazosin (10(-7)-10(-5) M). The 5HT-induced inhibition of twitch contractions in the presence of ketanserin was not antagonized by phentolamine, propranolol, methysergide, morphine, promethazine, cimetidine, atropine or indomethacin. It is suggested that 5HT has dual (excitatory and inhibitory) effects upon nerve transmission of rat vas deferens, and only the excitatory effect is suppressed by ketanserin.