Dynamics of Insulin Secretion by the Perfused Rat Pancreas

TLDR: The dynamics of insulin release in response to relatively long infusions of glucose were studied in the isolated perfused rat pancreas and Histological examination of the perfused pancreases and measurement of oxygen consumption by these tissues indicated that optimal physiological conditions were used.

Abstract: The dynamics of insulin release in response to relatively long infusions of glucose were studied in the isolated perfused rat pancreas. Insulin secretion was determined by immunochemical assay of the total portal vein effluent. Histological examination of the perfused pancreases and measurement of oxygen consumption by these tissues indicated that optimal physiological conditions were used. It was observed that, when glucose was infused for a period of approximately 1 hr into a perfused pancreas, there appeared 2 distinctly different phases of insulin release. There was an early, or rapid, release of insulin which subsided within approximately 2 min, followed by a late, or slow release phase which continually increased in rate until termination of the glucose infusion. The contribution of newly synthesized insulin to either phase was determined by comparing the insulin release by normal control preparations to that by preparations which were treated with puromycin. Incorporation of L-valine-14C was used a...