Effect of amylin on insulin secretion in rat pancreatic islets and its mechanism

To study the effect of Amylin on insulin secretion in rat pancreatic islet cells and its mechanism. Radio-immunological and fluorescence methods were used to determine the amount of insulin secretion as well as content of intracellular Ca~(++) and cAMP by the rat islet cells incubated with amylin in different concentrations. In the 10muM/L amylin group, the glucose-stimulated insulin release volume, intracellular Ca_(++) and cAMP content were 0.89±0.21ng/ml, 63±10nmol/L and 29.3±3.3pmol/L1×10~(6) cell respectively as compared with the control group (1.75±0.41ng/ml,135±10nmol/L and 36.3±7.4pmol/L×10~(6) cells respectively). The insulin release volume and intracellular Ca~(++) decreased remarkably(P<0.01), while cAMP content had a tendency to decrease. High concentration of amylin is responsible for the prevention of rise of Ca~(++) inside the islet B-cells and/or the decrease of cAMP content which is one of the causes that bring about the decreased release of insulin.