5-Hydroxytryptamine can antagonize the ability of metoclopramide and SCH 23390 to enhance electrical field stimulation-evoked contractions of guinea-pig isolated stomach muscle.
Electrical field stimulation of guinea-pig stomach strips caused frequency related contractions that were enhanced by metoclopramide and SCH 23390 (10(-7)-10(-5) M) and antagonized by atropine (5 X 10(-8) M. 5-HT (3 X 10(-8)-3 X 10(-5) M) antagonized the ability of metoclopramide and SCH 23390 to enhance the contractions. It is concluded that metoclopramide and SCH 23390 can enhance electrical field stimulation-induced contractions in the stomach strips by a 5-HT receptor blockade which can facilitate cholinergic mediated contractions.
Gunning
S J
SJ
Naylor
R J
RJ
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001552:Benzazepines / Q000494:pharmacology*; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008787:Metoclopramide / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology*; D013270:Stomach / Q000187:drug effects*
D014150:Antipsychotic Agents; D001552:Benzazepines; D011985:Receptors, Serotonin; D012701:Serotonin; D008787:Metoclopramide