Effect of ascorbic acid in the presence of neomycin on isolated rat stomach strips.
The effects of vitamin C and acetylcholine on the smooth muscle of rat stomach were compared after neomycin-induced blockade of phosphatidylinositol metabolism. The cumulative curves of dose-dependent responses showed a non-competitive antagonism between vitamin C and neomycin. On the other hand, the antagonism between acetylcholine and neomycin was of a mixed, competitive-non-competitive type. The results of the experiments suggest the conclusion that a normal metabolism of phosphatidylinositol controlling calcium transport into the cells is necessary for the stimulating effect of vitamin C on the contractions of the smooth muscles in the digestive tract.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D009355:Neomycin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013270:Stomach / Q000187:drug effects*
D009355:Neomycin; D000109:Acetylcholine; D001205:Ascorbic Acid