酚妥拉明对离体正常大鼠胰岛功能的影响

Effects of Phentolamine on the Function of Isolated Islets of Normal Rats

目的 探讨酚妥拉明对离体正常大鼠胰岛功能的影响。方法 胶原酶和DNA酶联合消化法分离SD大鼠胰岛 ,RP MI164 0组织培养液过夜培养 ,采用MilliporeMultiscreen系统观察不同浓度葡萄糖及酚妥拉明对胰岛功能的影响。放免法测定孵育液中胰岛素及胰高糖素的浓度。结果 ⑴离体胰岛胰岛素的分泌依赖于孵育液中的葡萄糖浓度 ,酚妥拉明明显刺激其释放。Ca2 +通道阻滞剂硝苯吡啶 (2 5 μmol/L)及K+ 通道开放剂二氮嗪 (10 0 μmol/L)可显著抑制胰岛素的释放 ,但其作用可被酚妥拉明消除。⑵离体胰岛胰高糖素的分泌明显受葡萄糖浓度的抑制 ,酚妥拉明显著抑制其分泌 ,其抑制作用呈明显的浓度依赖型 ,硝苯吡啶和二氮嗪也显著抑制胰高糖素的释放。结论 酚妥拉明可刺激离体胰岛胰岛素的释放 ,抑制胰高糖素的分泌 。

Objective To explore the effects of phentolamine on the function of the islets isolated from normal rats.Methods The SD rats islets were isolated by digestive method with collagenase and DNase.Millipore Multiscreen Assay System was used to observe the effects of phentolamine on the function of isolated islets. Insulin and glucagon were measured by RIA. Results ⑴Insulin secretion of the isolated islets incubated in culture medium was glucose concentration-dependent manner. Phentolamine had stimulate insulin secretion significantly. Nifedipine (Ca 2+ channel blocker) and diazoxide (K + channel opener) had inhibit the insulin release, but their effects were abolished by phentolamine. ⑵Glucagon secretion of the isolated islets in culture medium incubated was inhibited by glucose. Phentolamine inhibited glucagon secretion significantly, and the inhibiting effect was also concentration-dependent manner,both the nifedipine and diazoxide had the effect too. Conclusion Phentolamine could stimulate insulin secretion, and inhibit glucagon secretion in the isolated islets.It maybe has some hypoglycemic effects on diabetes.