Study of glucagon secretion using in vitro perifusion of rat pancreas pieces

The in vitro perifusion technique of rat pancreatic tissue has been studied in respect of sensitivity and reproducibility regarding alpha-2-cell function. Convenient and quickly performed, it allows the kinetic analysis of humoral factors of glucagon release when the blood vessels are too small to be cannulated, for instance in case of fetal pancreas and of tumor tissue. A2 cells in the perifused pancreatic tissue release glucagon in response to arginine, norepinephrine and the decrease of glucose concentration in the medium. The sensitivity of this preparation is lower than that of the perfused pancreas: this may be related to unphysiological conditions of fluid circulation, of the degradation of the stimuli and degradation of the hormone released. Satisfactory conditions of perifusion flow rate and amount of panceatic tissue have been defined and several protective agents have been tested.