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Updated: Jun 28, 2026

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination
Published on: June 25, 2014
Somatostatin secreted by islet delta-cells fulfills multiple roles as a paracrine regulator of islet function
Astrid C Hauge-Evans1, Aileen J King, Danielle Carmignac
1Beta Cell Development and Function Group, Division of Reproduction and Endocrinology, King's College London, London, UK. astrid.hauge_evans@kcl.ac.uk
Objective:
Somatostatin (SST) is secreted by islet delta-cells and by extraislet neuroendocrine cells. SST receptors have been identified on alpha- and beta-cells, and exogenous SST inhibits insulin and glucagon secretion, consistent with a role for SST in regulating alpha- and beta-cell function. However, the specific intraislet function of delta-cell SST remains uncertain. We have used Sst(-/-) mice to investigate the role of delta-cell SST in the regulation of insulin and glucagon secretion in vitro and in vivo.
Research Design And Methods:
Islet morphology was assessed by histological analysis. Hormone levels were measured by radioimmunoassay in control and Sst(-/-) mice in vivo and from isolated islets in vitro.
Results:
Islet size and organization did not differ between Sst(-/-) and control islets, nor did islet glucagon or insulin content. Sst(-/-) mice showed enhanced insulin and glucagon secretory responses in vivo. In vitro stimulus-induced insulin and glucagon secretion was enhanced from perifused Sst(-/-) islets compared with control islets and was inhibited by exogenous SST in Sst(-/-) but not control islets. No difference in the switch-off rate of glucose-stimulated insulin secretion was observed between genotypes, but the cholinergic agonist carbamylcholine enhanced glucose-induced insulin secretion to a lesser extent in Sst(-/-) islets compared with controls. Glucose suppressed glucagon secretion from control but not Sst(-/-) islets.
Conclusions:
We suggest that delta-cell SST exerts a tonic inhibitory influence on insulin and glucagon secretion, which may facilitate the islet response to cholinergic activation. In addition, delta-cell SST is implicated in the nutrient-induced suppression of glucagon secretion.
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