The effects of some sympathomimetic amines and cocaine hydrochloride on the intact intestine of the unanesthetized dog

All except one of the pure crystalline sympathomimetic amines, L-epinephrine bitartrate; L-nor-epinephrine bitartrate; D-epinephrine bitartrate; D-nor-epinephrine bitartrate; L-D-isopropylarterol hydrochloride (Isuprel); amphetamine sulfate (Benzedrine sulfate); phenylephrine hydrochloride (Neo-Synephrine) and Epinine used, when given in adequate dosage, caused an inhibition of the contractions of the intestine with a decrease in its general tonus. The only exception is, D-1-isopropylarterenol hydrochloride (Isuprel). This amine caused an increase in the general tonus with small doses and an increase followed by a decrease in the general tonus with large doses. The L-epinephrine series was found to be at least ten times as potent on the intestine as the D-epinephrine series. Cocaine administered before injections of L-epinephrine or L-nor-epinephrine definitely potentiates the effects of these latter drugs. It has a variable influence upon the effects of phenylephrine hydrochloride and Epinine and decreases the responses of the gut to all of the other sympathomimetic amines studied.