Dynamic analysis of secretagogue-induced amylase secretion from rat pancreatic acini studied by perifusion system

A perifusion system was applied for the study on stimulus-enzyme secretion coupling in dispersed pancreatic acini. The system is highly simple, preserves the acini up to more than 3 hr, and makes feasible clear-cut examination on the time course of enzyme secretion caused by secretagogues. Caerulein (10(-9) M) and carbamylcholine (10(-5) M) caused a biphasic amylase secretory pattern consisting of an initial burst secretion and a sustained one. Caerulein induced a persistent amylase release even after cessation of the stimulation, while carbamylcholine-stimulated amylase release returned to basal levels. Atropine inhibited completely carbamylcholine-stimulated amylase release and the successive stimulation by caerulein evoked the amylase secretion with a decreased initial burst secretion. In calcium free medium, caerulein and carbamylcholine induced only a slight secretion, particularly in the sustained secretion phase and a gradual increase occurred with the addition of calcium.