Secretagogue response in rat pancreatic acinar carcinoma.

The secretion of protein, like cell proliferation, is an integrated response that reflects structural organization of the cell periphery. Stimulation of protein secretion was thus utilized for comparison of integrated responses of the cell periphery in pancreatic acinar carcinoma of the rat and integrated responses in normal rat pancreas. Results of this comparison include: a) The stimulation of protein secretion in acinar carcinoma fragments by carbamylcholine chloride and cholecystokinin octapeptide, pancreatic secretagogues that interact with specific plasma membrane receptors, was only a fraction (one-fifth to one-half) of that observed in normal pancreatic minilobules. b) The Ca2+ ionophore A23187 and the cyclic nucleotide N6,O2'-dibutyryl cyclic AMP, secretagogues that act independently of specific membrane receptors, did not stimulate secretion in the acinar carcinoma. The observed quantitative and qualitative differences in protein secretion indicate fundamental differences in cell periphery organization between the normal and transformed acinar cells of pancreas.