Difference in dose-response curves for glucose-induced insulin and somatostatin release in rat pancreas.

We studied the glucose dependence of insulin and somatostatin release from rat pancreata, which were perfused in vitro in the presence of 3-isobutyl-1-methylxanthine (IBMX; 0.5 mM). Half-maximal insulin release occurred at approx. 12 mM glucose, and half-maximal somatostatin release at approx. 7 mM glucose.