Secretagogues for lysosomal enzyme release as stimulants of arachidonyl phosphatidylinositol turnover in rabbit neutrophils

Abstract

Summary [ 14 C]arachidonic acid incorporation into phosphatidylinositol from rabbit neutrophils pretreated with cytochalasin B was increased within 2 min by the synthetic peptide formyl-methionyl-leucyl-phenylalanine and the Ca 2+ ionophore A23187. A high concentration of the peptide elicited only a small increase in phosphatidylinositol turnover when [ 14 C]palmitic acid was employed as precursor. These data coincide with our earlier studies which identified a Ca 2+ -dependent increase in arachidonyl phosphatidylinositol turnover during adrenocorticotropin and A23187-induced activation of steroid production and release in adrenocortical cells. It is concluded that an increase in arachidonyl phosphatidylinositol turnover mediated by a Ca 2+ -dependent phospholipase A 2 may be a general mechanism for altering membrane function during secretory activity.