Linoleic acid is a potent activator of protein kinase C type III-alpha isoform in pancreatic acinar cells; its role in amylase secretion

Linoleic acid, an unsaturated-long chain fatty acid, was found to maximally activate protein kinase C (PKC) more effectively than arachidonic or linolenic acid, while the saturated fatty acids palmitic or arachidic had no stimulatory effect. Treatment of intact pancreatic acinar cells with linoleic acid resulted in dose-dependent phosphorylation of endogenous substrate proteins for this kinase and simultaneously stimulated amylase secretion in a dose- and time-dependent fashion. During chromatographic separation of pancreas protein kinase C activity, utilizing hydroxylapatite (HTP), Type III-alpha PKC isoform was detected. These data are consistent with a role for PKC in the regulation of pancreatic exocrine secretion.