Action of Reserpine on Isolated Intestinal Muscle

Abstract

CERTAIN intermediates of the tricarboxylic acid cycle antagonize the reserpine inhibition of contractions induced by drugs of isolated guinea pig ileum¹ (Table 1). We have observed that the most effective reserpine antagonists were those added as the free acids. These reduced the reaction of the bath–fluid to about pH 5. When the reaction was reduced to similar levels by the addition of small volumes of 0.2 N hydrochloric acid, antagonism to reserpine was also seen. This was less marked, however, than that following addition of the most effective metabolites, which included α-ketoglutaric acid (1 mgm. per ml.) and cis-aconitic acid anhydride (1 mgm. per ml.). At a bath pH of 7.4, no antagonism to reserpine was seen.