高糖对大鼠离体胰岛胰岛素分泌的影响

Effect of Hyperglycemia on Insulin Release from Isolated Rat Pancreatic Islets

经胶原酶分离、培养的大鼠胰岛,其形态、结构完整。长时间(24h)暴露于高浓度葡萄糖(简称高糖,下同)环境中(26.4mmol/L)的胰岛,与新分离的胰岛相比,温育时胰岛素的基础分泌(2.8mmol/L葡萄糖)增加(P<0.01);而对高糖(16.7mmol/L)刺激的分泌则降低(P<0.05),且此作用具有时间依赖性。长时间高糖培养后的胰岛灌流时亦可见基础分泌显著增加,高糖刺激的胰岛素分泌第一时相消失,第二时相幅度明显降低。高糖培养后的胰岛对精氨酸的敏感性增加,高糖培养对精氨酸刺激的胰岛素分泌有显著的加强作用。人参总皂甙能显著提高胰岛对葡萄糖刺激的反应性。

We investigated the long-term ( 2Λh ) influence of high concentration glucose (26. 4mmol/L)on insulin release by culturingcoll genase isolated rat pancr eatic islets in vitro. The cultured islets were morphorlogically normal by his-tological examination. Compared with freshly isolated islets, islets cultured in 26.4mmol/L glucose showed higher basal insulin release (P<0. 05). The effect of high glucose was time dependence. When islets preexposed to high glucose medium for 24h were perfused, the basal insulin release was significantly higher than that of freshly isolated islets, the first-phase glucose stimulated insulin release disappeared, and the second-phase was diminished. Islets cultured in high glucose medium showed increased sensitvity to L-arginine. Long -term high concentration glucose could potentiate the argine-induced release. When added to the culture medium with 26.4mmol/L glucose,Ginseng saponins markedly increased the responsiveness of islets to glucose stimulation, and augmented the sensitivity of incubated islets to additional Ginseng saponins.