Cytochalasin B: effect on phospholipid metabolism and lysosomal enzyme release by leukocytes;

Abstract

The effect of cytochalasin B on phospholipid metabolism and beta-glucuronidase extrusion by polymorphonuclear leukocytes from guinea pid peritoneal exudates has been studied. Cytochalasin B inhibited the engulfing of starch granules by leukocytes, but it enhanced the incorporation of 32-Pi into phosphatidic acid and the phosphoinositidesmit also stimulated the release of beta-glucuronidase into the incubation medium in the presence or absence of starch granulesmkinetic studies showed that the effects of cytochalasin B on 32-Pi incorporation into phosphatidic acid and the phosphoinositides, and the release of beta-glucuronidase into the extracellular medium were comparablempulse-chase experiment revealed that cytochalasin B did not stimulate the isotopic decay of prelabeled lipids, indicating that cytochalasin B increased the radiophosphorus activity of phosphatidic acid and the phosphoinositides by increasing the synthesis of these lipidsmthe incorporation of myo-[2-3H]inositol into the phosphoinositides was also enhanced in the presence of cytochalasin B, but the incorporation of [methyl-14-C] choline into phosphatidylcholine and sphingogonyelin was unchanged;