RT Journal Article SR Electronic T1 THE ACTION OF SYNTROPAN ON THE GASTROINTESTINAL TRACT JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 464 OP 478 VO 66 IS 4 A1 BYRON B. CLARK A1 E. B. S. SHIRES, JR. A1 E. H. CAMPBELL A1 C. STUART WELCH YR 1939 UL http://jpet.aspetjournals.org/content/66/4/464.abstract AB 1. Syntropan in small amounts effectively antagonizes stimulation by drugs of the parasympathetic mechanism of excised intestine without muscular depression. 2. Larger amounts of syntropan produce some direct muscular depression of excised intestine. 3. Syntropan depresses the activity of the duodenum in the unanesthetized dog with less effect upon heart rate, pupil size, and salivation than atropine. 4. About 100 times more syntropan than atropine is required to produce the same degree of depression of intestine. 5. In the unanesthetized dog, syntropan antagonizes the stimulating effect of mecholyl, morphine and pitressin. 6. The antagonism of morphine and pitressin by syntropan is much greater than for an equivalent dose of atropine and suggests that antagonism of smooth muscle stimulants may be obtained by syntropan in the intact animal. 7. Syntropan produces relaxation of the tone of the stomach and inhibition of peristaltic activity. 8. The effect of syntropan on gastric secretion excited by a meat extract meal and histamine is weak as compared with atropine.