Galanin and the endocrine pancreas

FEBS Letters

Rorsman, Patrik³  Ahrén, Bo²  Berggren, Per-Olof¹ 

[1]Department of Medical Cell Biology, University of Uppsala, Uppsala, Sweden

[2]Department of Pharmacology, Lund University, Lund, Sweden

[3]Department of Medical Physics, Gothenburg University, Gothenburg, Sweden

关键词: Galanin;    Insulin secretion;    Glucagon secretion;    Somatostatin secretion;    Pancreatic polypeptide secretion;    Ca2+;    (Pancreas;    Islets of Langerhans);   

DOI  :  10.1016/0014-5793(88)81131-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Galanin is a 29 amino acid peptide, initially isolated from the porcine small intestine. The peptide has been shown to occur in intrapancreatic nerves in close association to the islets. Its effects on islet hormone secretion and its possible mechanisms behind these effects are reviewed. Galanin has been shown to inhibit basal and stimulated insulin secretion both in vivo and in vitro under a variety of experimental conditions. The peptide has also been shown to inhibit somatostatin secretion and the secretion of pancreatic polypeptide (PP). With regard to glucagon secretion, however, results in the literature are not consistent since both stimulatory and inhibitory effects have been reported. A direct interaction with the pancreatic β-cells has been proposed behind its inhibitory action on insulin secretion, since galanin inhibits insulin secretion from isolated β-cells from obese, hyperglycaemic, mice. Galanin has thereby also been shown to induce repolarization and to reduce the free Ca²⁺ concentration, [Ca²⁺]_i. The reduction in [Ca²⁺]_i is probably not due to a direct interference with the voltage-activated Ca²⁺ channels, since there is no effect of galanin when these channels are opened by depolarization induced by high concentrations of K⁺. Instead, preliminary studies indicate that galanin activates the K⁺ channels that are regulated by ATP, in turn inducing a repolarization-induced reduction in [Ca²⁺]_i resulting in reduced insulin secretion. However, the possibility that galanin inhibits the insulin secretory mechanism at a step distal to the regulation of cytoplasmic free Ca²⁺ concentration should not be overlooked.

【 授权许可】

Unknown