Effect of DA on insulin secretion fromrat pancreatic cells and possible mechanism / 中国药理学通报

ABSTRACT

Aim To investigate the effects of dopamine(DA)on insulin secretion from rat islets and the possible mechanism.Methods Pancreatic islets were obtained from the pancreatic of male SD rats by collagenase P digestion and histopaque-1077 density gradient separation.Insulin secretion experiment was used to observe the change of insulin release after DA treatments.As to study the potential mechanisms of the effects of DA,patch-clamp experiment and calcuim image technique were applied to test the depolarization-evoked Ca2+ currents,action potential duration and intracellular Ca2+ concentration.Results In 2.8 mmol·L-1 glucose,DA had no effect on insulin secretion;in 16.7 mmol·L-1 glucose,dopamine inhibited insulin secretion in a dose-dependent manner.DA inhibited the inward calcium current,shorten the action potential duration,and reduced the intracellular Ca2+ concentration.Conclusion DA inhibits insulin secretion maybe by decreasing the inward calcium current leading to shorten the action potential duration and reduce the intracellular Ca2+ concentration.