Bacitracin U.S.P. contains a factor that stimulates receptors for 5-hydroxytryptamine on rabbit aortic strips.
Bacitracin (BAC) U.S.P., obtained in the form of sterile powder, elicits dose-dependent and non-tachyphylactic contractions of the rabbit isolated aorta and of other rabbit vessels. The use of several pharmacologic antagonists suggests that BAC is a 5-hydroxytryptamine mimetic in aortic strips, since the antibiotic is competitively antagonized by methysergide and ketanserin with pA2 values compatible with an agonist action on the 5-HT2 receptors found in the aortic preparation. It remains to be determined whether bacitracin A, the chief constituent of BAC U.S.P., is the 5-HT agonist.
deBlois
D
D
Department of Pharmacology, Faculty of Medicine, Université Laval, Cité Universitaire, Québec, Canada.
Bouthillier
J
J
Marceau
F
F
D000818:Animals; D001011:Aorta / Q000187:drug effects; D001414:Bacitracin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
D011985:Receptors, Serotonin; D001414:Bacitracin