Influence of stepwise uncoupling and temporary anoxia on pancreatic enzyme secretion by isolated rat acini

For special studies on pancreatic diseases a parameter is needed to record alterations of the cellular energy metabolism. In the in vitro model of isolated pancreatic acini, we investigated whether or not at standardized cholecystokinin stimulation the energy-consuming process of enzyme secretion can be used to monitor changes of the energy-supplying capacity. Rat pancreatic acini were isolated via collagenase digestion and characterized by basal and stimulated release of amylase and trypsin, oxygen uptake under resting and maximally uncoupled conditions and by their ability to accumulate actively rhodamine-6G, as a measure of the mitochondrial membrane potential. The stimulation of enzyme release did not find a measurable reflection in rhodamine-6G accumulation and in the respiratory rat. Stepwise uncoupling of oxidative phosphorylation by 2,4-dinitrophenol (DNP) and temporary anoxia were used to simulate disturbances of the pancreatic energy metabolism in vitro. With increasing DNP concentration the enzyme release was significantly reduced. While after 30 min anoxia the enzyme release still exceeded that of unstimulated control, after 60 min anoxia there was no further response to hormonal stimulation. At standardized stimulation and after suitable calibration the enzyme release by acini may be used to monitor alterations of the pancreatic energy metabolism in vitro.