The effect of thymoxamine on guinea-pig ileum contractions.
The effects of thymoxamine on the contractions induced in guinea-pig isolated ileum were examined. The drug was tested in a large range of concentrations (10(-8)-10(-4) M). The twitch response induced by acetylcholine was potentiated by low concentrations and inhibited by high concentrations of the alpha 1-blocking drug thymoxamine. The contractions in response to carbachol were always inhibited. Thymoxamine also affected the responses of the ileum to other stimulants: angiotensin, pentagastrin, cholecystokinin. The drug (8 X 10(-5), 5 X 10(-4) M) inhibited the calcium contraction of high K+ depolarized preparations.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D013948:Moxisylyte / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects
D002800:Cholinesterase Inhibitors; D011942:Receptors, Adrenergic, alpha; D013948:Moxisylyte; D002118:Calcium