RT Journal Article SR Electronic T1 THE EFFECT OF ACID ON THE GUINEA PIG ILEUM CONTRACTED BY ACETYLCHOLINE AND HISTAMINE JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 253 OP 257 VO 57 IS 3 A1 JAMES W. SACHS A1 JOSEPH McK. IVIE YR 1936 UL http://jpet.aspetjournals.org/content/57/3/253.abstract AB 1. Approximately twice the amount of acetic acid is needed to relax an intestinal strip when contracted by acetylcholine than when contracted by histamine. 2. The amount of acid necessary to cause relaxation is dependent within limits on the amount of histamine but independent of the amount of acetylcholine used. 3. Lactic acid has the same effect as acetic acid. 4. Increasing the calcium concentration has no effect on the acid relaxation.