Effect of substance P on contractions of the gallbladder.
The effect of substance P on contractions of the gallbladder in dogs (in vivo) and rabbits (in vitro) was examined. Substance P stimulated contraction of the gallbladder, both in vivo and in vitro; however, substance P was not as effective as cholecystokinin. Stimulation of gallbladder contractions in vivo by substance P was not affected by atropine. Stimulation of gallbladder strips in vitro by substance P was not affected by adrenergic antagonists or tetrodotoxin. These findings suggest that substance P may be a direct stimulant of contraction of the smooth muscle of the gallbladder.
D000818:Animals; D002766:Cholecystokinin / Q000008:administration & dosage / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004341:Drug Evaluation; D005704:Gallbladder / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D011817:Rabbits; D013373:Substance P / Q000008:administration & dosage / Q000494:pharmacology*
D013373:Substance P; D002766:Cholecystokinin