Effect of GIP on the secretion of insulin and somatostatin and the accumulation of cyclic AMP in vitro in the rat

in European Journal of Endocrinology
Restricted access


The effects of gastric inhibitory polypeptide (GIP) on insulin secretion as well as on the intra-islet accumulation of [3H]cyclic AMP were investigated in isolated pancreatic islets of the rat. In the presence of 6.7 mmol/l of glucose, 3.0 and 30 nmol/l of GIP induced both insulin and [3H]cyclic AMP responses, while lower and higher concentrations of the peptide were ineffective. A coupling of the two parameters was also found with regard to interaction between glucose and GIP. Thus while 30 nmol/l of GIP was stimulatory together with 6.7, 16.7 or 33.3 mmol/l of glucose, the peptide stimulated neither insulin release, nor the accumulation of [3H]cyclic AMP in the presence of a low concentration of glucose (3.3 mmol/l).

The concomittant release of insulin and somatostatin was studied in the perfused pancreas in order to assess a possible influence by somatostatin on the dose-response pattern for GIP-induced insulin release. In this preparation 1.0 to 10 nmol/l of GIP stimulated insulin and somatostatin secretion; however while these concentrations were equipotent on insulin release, 10 nmol/l of GIP stimulated somatostatin release more than 1 nmol/l, indicating differences in dose-reponse curves for the GIP-induced stimulation of the two hormones.

It is concluded that 1) modulation of GIP-induced insulin release is coupled to changes in cyclic AMP response in the islet, 2) GIP-induced somatostatin secretion may influence the concomittant insulin response.


     European Society of Endocrinology

Related Articles

Article Information


All Time Past Year Past 30 Days
Abstract Views 66 66 1
Full Text Views 72 34 0
PDF Downloads 52 21 0


Cited By


Google Scholar