STIMULUS-SECRETION PATHWAY FOR HISTAMINE IN THE EXOCRINE PANCREAS

An investigation was carried out on the effects of histamine on amylas e secretion and its stimulus-secretion coupling mechanism in isolated guinea-pig pancreatic acinar cells. The effects of acetylcholine (ACh) and vasoactive intestinal peptide (VIP) were evaluated for comparison . Histamine, ACh and VIP individually evoked significant increases in amylase release. Histamine had no detectable effect on intracellular f ree calcium concentration ([Ca2+](i)), compared to a much larger respo nse obtained when ACh was tested. The stimulatory effect of histamine and VIP on amylase release was accompanied by increases in cyclic aden osine monophosphate (cAMP) levels. These results appeal for the involv ement of histamine in the control of amylase secretion and cyclic AMP system in guinea-pig pancreatic acinar cells.