Calphostin C, a Potent and Specific Inhibitor of Protein Kinase C, Reduces Phorbol Ester-Induced but Not Primary Ca2+-Induced Catecholamine Secretion from Digitonin-Permeabilized Bovine Adrenal Medullary Cells

Calphostin C, a protein kinase C inhibitor, reduced phorbol ester-induced enhancement of catecholamine secretion but not primary Ca2+-induced secretion from digitonin-permeabilized bovine adrenal medullary cells, indicating that this compound selectively inhibited protein kinase C-dependent secretion.