In vitro perfusion and incubation of rat pancreatic lobules in a kinetic system

The use of pancreatic lobule preparations is one of the well-established approaches to study stimulus-secretion coupling in the exocrine pancreas in vitro. We have developed a kinetic system for the perfusion and intermittent incubation of rat pancreatic lobules. This model allows repeated hormone stimulation for up to 3 h while permitting rapid changes of the cellular environment with no accumulation of secretory or metabolic products. Tissue viability could be demonstrated over 6 h by in vivo toluidine blue exclusion, histology and electron microscopy. Lactate dehydrogenase leakage from cells over 6 h was only 2.4% of total content. No activated trypsin was detected in the perfusion medium. A biphasic dose response was established for cholecystokinin stimulation with a maximal response at 10(-8) M. We conclude that kinetic perfusion and incubation are technically feasible with rat pancreatic lobules. This in vitro model appears particularly suited for the investigation of pharmacologic and metabolic effects on the pancreatic acinar cell when rapid changes of the cellular environment are required and when the accumulation of secretory and metabolic products must be avoided. The technique described requires neither protease inhibition in the medium nor collagenase treatment of the cells.