Effect of somatostatin on glucose induced insulin release in isolated perfused rat pancreas and isolated rat pancreatic islets

Inhibition by somatostatin of glucose induced 3′: 5′‐monophosphate (Cyclic AMP) accumulation and insulin release in isolated pancreatic islets of the rat

“…In a previous paper we were unable to inhibit glucose stimulated insulin release from rat islets with 200 ng/ml of somatostatin [4]. In the present experiments, the administration of 500 ng/ml was accompanied by a definite inhibition of insulin release.…”

“…By increasing the dose to 100 ng/ml, an almost complete inhibition of basal as well as stimulated insulin release was observed. On the other hand, somatostatin in concentrations up to 200 ng/ml did not influence glucose stimulated insulin release from isolated rat islets [4].…”

“…There is ample evidence that somatostatin inhibits insulin release induced by glucose [1][2][3][4][5], glucagon [9], isoproterenol [10], theophylline [10] and tolbutamide [9]. All these insulinogogues have in common stimulation of production of cyclic AMP in the islets.…”

“…It has been demonstrated that the hypothalamic growth hormone (GH) release inhibiting factor, somatostatin, also suppresses glucose induced insulin release in man [1][2][3] and in the isolated perfused pancreas from the dog [1] and rat [4,5]. In the latter preparation the lowest effective dose of somatostatin was 1 ng/ml of perfusate.…”

Inhibition by somatostatin of insulin release from isolated pancreatic islets

“…As for the insulin secretion, somatostatin was reported to suppress a glucoseinduced rise of plasma insulin in humans [2] and to inhibit insulin secretion by perfused pancreases [2-41. However, concerning its direct effect on insulin release from the pancreatic islet of Langerhans there have so far been two controversial results; Although Efendic et al [3] failed to demonstrate the inhibitory effect of somatostatin on insulin release from the isolated islet, Oliver and Wagle [5] have quite recently reported that the inhibition of insulin release from the islet was observed in experiments with incubation media containing somatostatin concentrations ranging from 0.2 to 100 pglml.…”