长期酒精摄入对大鼠胰岛的影响及与氧化应激关系的探讨

目的　探讨了活性氧和一氧化氮 (NO)在其中的可能作用 ,以研究长期酒精摄入对胰岛影响的机制。方法　对照组灌以 6ml kgBW的蒸馏水 ,低、中、高各剂量组的无水乙醇剂量分别为 0 4 8、1 4 4及 2 4 0g kgBW ,时间为 1 3周。实验结束时检测了血糖和血胰岛素 ,用免疫组化及图象分析法分析了大鼠的胰岛结构参数 (从各组随机选 1 0只 ) ,并检测了其余大鼠血清和胰腺组织中的自由基反应水平。结果　 (1 )与对照组相比 ,高剂量组雌雄大鼠的血糖升高 ,血胰岛素下降 ,胰岛素免疫反应阳性物面积与胰腺组织面积百分比(Ins+ panc)及胰岛素免疫反应阳性物面积与胰岛组织面积百分比 (Ins+ Isl)均降低 (P <0 0 5 )。 (2 )与对照组相比 ,高剂量组雌雄大鼠血清和胰腺组织中的总超氧化物歧化酶 (T SOD)降低 ,NO、活性氧及丙二醛 (MDA)含量升高 ;而低剂量组雌雄大鼠血清中的T SOD和谷胱甘肽过氧化物酶 (GSH Px)升高 ,NO、活性氧及MDA含量下降 (P <0 0 5 )。结论　长期过量饮酒可通过引起胰腺氧化损伤而使胰岛功能受损 ,这可能是酒精引起患糖尿病危险性增高的原因之一。而长期适量饮酒可使抗氧化能力增强 ,对机体有一定的保护作用

Effect of chronic alcohol administration on pancreatic islets and oxidative stress of rats

Objective To study the role of reactive oxygen species(ROS) and nitric oxide(NO) in the effect of chronic alcohol administration on pancreatic islets. Methods A oral administration of alcohol(6ml/kgBW) in different concentration (10%,30% and 50%) was given to rats for 90 days. Results The fasting serum glucose was markedly increased while fasting serum insulin was markedly reduced in high dose alcohol group in comparison with that in control group. Compared with control rats, we observed the significant decrease of the ratio of insulin immune active product area to pancreas area as well as that to islets area in high dose alcohol group. Compared with control rats, there were significant increase of ROS level, NO content and malondialdehyde(MDA) content, and significant decrease of total superoxide dismutase(T SOD) activity in serum and pancreas homogenate in high dose alcohol group. Our observations indicate that ROS and NO play an important role in the effect of chronic alcohol administration on pancreatic islets of rats. Conclusion Free radicals in pancreas induced by chronic administration of high dose alcohol caused oxidative injuries of pancreatic islets.