[The M-receptor stimulation of phosphatidylinositol metabolism in the isolated rabbit heart].

Abstract

The activating effect of a M-receptor agonist carbachol on phosphatidylinositol metabolism under perfusion of the isolated rabbit heart with 32Pi was shown. An increase of the inclusion of 32P in phosphatidylinositol-4-phosphate and phosphatidylinositol-4-diphosphate was found. Simultaneously there was detected an elevation of the levels of products of hydrolysis of inositol phospholipids--inositol-1,4-diphosphate and inositol-1,4,5-triphosphate. There was noted the blocking action of carbachol on the contractile activity of the heart that manifested itself in a lowering of the systolic pressure in the left ventricle and a slowing of the contraction rate.