Effects of galanin on electrical activity of pancreatic islet cells

Intracellular microelectrode technique was used to investigate the effect of galanin on the electrical activity of beta cells of Langerhans islets of mice. Galanin 0.15 and 0.3 mumol/L in the perfusion medium inhibited the basic electrical activity induced by glucose 5.5, 11.1 and 20 mmol/L in decreasing the frequency and amplitude of the spikes. In some cells, during galanin inhibition there was a hyperpolarization after the spike. Verapamil (30, 60 and 90 mumol/L), a blocker of voltage-dependent Ca channels, blocked dose-dependently the electrical activity induced by glucose and attenuated the depolarization induced by KCl 50 mmol/L. Galanin 0.3 mumol/L also attenuated the depolarization induced by KCl 50 mmol/L, similar to the effect of verapamil. The results suggest that the effect of galanin on inhibition of the electrical activity of beta cell might be due to blocking of voltage-dependent Ca2+ channels.