Galanin-induced inhibition of insulin release from cultured rat islets

To determine the effect of galanin on insulin secretion from islets of Langerhans in vitro, isolated rat islets were cultured in the medium containing various concentrations of galanin and glucose. Insulin secretion was inhibited markedly and dose-dependently by galanin. when the glucose concentration in the culture medium was 5.5 mmol/L. Galanin 0.3 vmol/L had a more pronounced inhibitory effect on insulin secretion in culture medium with a glucose concentration of 5.5 mmol/L than in medium with 2.7 or 20 mmol/L of glucose. Without glucose in the medium, galanin had a negligible effect on insulin secretion from the cultured islets, Galanin did not affect glucagon release. In conclusion, galanin inhibits effectively insulin release from isolated islets. thus suggesting that it may act as a modulator in controlling insulin secretion from pancreatic beta cells under normal physiological conditions.