胰淀素对大鼠胰岛素和胰高血糖素分泌的影响

目的研究胰淀素对大鼠胰岛素和胰高血糖素分泌的影响。方法应用胶原酶消化和不连续密度梯度离心技术建立离体大鼠胰岛模型,研究不同浓度胰淀素对胰岛素和胰高血糖素分泌的影响。结果不同浓度的葡萄糖增加胰岛素的分泌,抑制胰高血糖素的分泌,并都呈线性相关。葡萄糖浓度为0、5.6、11.2mmol/L时,孵育1h,胰淀素(10-10~10-5mol/L)显著抑制胰高血糖素的分泌(P<0.05),且胰高血糖素的分泌与胰淀素浓度呈负相关(P<0.01)。葡萄糖浓度为5.6mmol/L时,不同浓度的胰淀素增加胰岛素分泌,而且两者呈正相关(P<0.05);但葡萄糖浓度为11.2和16.7mmol/L时,10-5mol/L胰淀素对胰岛素的分泌有明显抑制作用(P<0.05)。结论胰淀素对胰高血糖素的分泌有直接抑制作用;在葡萄糖浓度为5.6mmol/L时,胰淀素能增加胰岛素分泌,抑制胰高血糖素分泌;高糖时,高浓度的胰淀素抑制胰岛素分泌。

Effect of Amylin on Secretion of Insulin and Glucagon in Rats

Objective To study the effect of amylin on the secretion of glucagon and insulin in isolated rat islets. Methods The models of isolated rat islets were established by collagenase digestion and dextran gradient centrifugation. The influence of various concentrations of amylin on both glucagon and insulin secretion was studied. Results Various concentrations of glucose increased the insulin secretion and decreased the glucagon secretion.Compared with the control, islets exposed to amylin (10~ -10 to 10~ -5 mol/L) for 1 hour showed decreasing glucagon secretion as the glucose increased (0, 5.6 and 11.2 mmol/L) (P<0.05), and glucagon secretion was negatively correlated with the concentrations of amylin (P<0.01). The concentrations of amylin increased the insulin secretion at 5.6 mmol/L glucose, and insulin secretion was positively correlated with the concentrations of amylin (P<0.05). Insulin secretion was decreased by 10~ -5 mol/L amylin at 11.2 and 16.7 mmol/L glucose. Conclusion Amylin plays a directly inhibiting role in glucagon secretion. Amylin increases insulin secretion and decreases glucagon secretion at 5.6 mmol/L glucose. High concentrations of amylin decrease s insulin secretion at high concentrations of glucose.