α-硫辛酸对链脲菌素诱发的大鼠胰岛β细胞损伤的保护作用

目的 研究α-硫辛酸(ALA)对链脲菌素(STZ)诱导的糖尿病大鼠胰岛β细胞损伤的保护作用.方法 30只SD大鼠按数字随机法分为正常对照组(NC组)、STZ组和ALA+STZ组(ALA组),各10只.后2组以STZ(70 mg/kg体重)一次性腹腔内注射诱发糖尿病,ALA组在注射前8 d开始给予ALA(50 mg·kg-1·d-1,强饲)直至实验结束(4周).STZ注射后每3天监测血糖、体重一次.测定胰腺匀浆中丙二醛(MDA)含量及还原型谷胱甘肽(GSH)水平,免疫组化方法检测胰岛β细胞内胰岛素水平.结果 STZ使大鼠血糖明显升高,STZ和ALA组制模成功率分别为90%(9/10)和70%(7/10),相差显著(P<0.05).实验结束时NC组、STZ组和ALA组平均体重分别为(368±3)g、(301±2)g和(341±26)g,3组间相差显著(P<0.05).STZ组胰腺组织内MDA水平为(1.22±0.14)nmol/mg prot,NC组为(0.57±0.04)nmol/mg prot,相差显著(P<0.05);STZ组胰腺组织内GSH含量为(16.54±1.10)mg/g prot,NC组为(25.46±0.62)mg/g prot(P<0.05);STZ组胰岛细胞呈退行性变.ALA组血糖较STZ组明显降低(P<0.05),胰腺组织匀浆MDA含量为(0.72±0.23)nmol/mg prot,较STZ组明显降低(P<0.05),GSH含量为(35.33 4±2.66)ms/s prot,较STZ组明显升高(P<0.05),胰岛的胰岛素分泌增强,较STZ组显著(P<0.05),胰岛β细胞损伤减轻.结论 ALA可通过减轻氧化应激来保护胰岛β细胞结构和功能的完整性.

Protective effects of alpha-lipoic acid against beta-cell damage in streptozotocin induced diabetes In rats

Objective To investigate the protective effects of alpha-lipoie acid (ALA) against beta-cell damage in streptozotocin (STZ)-induced diabetes in rats. Methods Thirty SD rats were randomly divided into three groups: normal control (NC) group, STZ group and ALA + STZ group, with 10 rats in each group. mg/kg, intraperitoneal injection), till the end of the study (4 weeks later). Blood glucose were measured every 3 days after STZ injection. Malondialdehyde (MDA) and reduced glutathione (GSH) levels were measured in pancreatic homogenates. Pancreatic beta-cells were examined by immunohistocbemical methods, Results STZ induced a significant increase of the level of blood glucose. Body weight of rats in ALA + STZ group was (341±26)g, which significantly lower than (368±3)g in NC group, and high than (301±2)g in STZ group with stas(P < 0. 05). Meanwhile the MDA levels in STZ group and NC group were(1.22 ± 0. 14) and(0.57 ± 0.04)nmoL/mg prot, respectively, and there was significant difference between the two groups (P < 0.05) ; the GSH levels in STZ group and NC group were(16.54 ± 1.10) and(25.46 ± 0.62) mg/g prot (P < 0.05), respectively; degeneration of islet cells and decreased blood glucose were observed in STZ + ALA-pretreated rats; MDA level in pancreatic homogenates was(0.72 ± 0. 23)nmoL/mg prot, which was significantly lower than that in STZ group (P < 0.05) ; the GSH level was (35.33 ± 2.66) mg/g prot, which was significantly higher than that in STZ group (P < 0.05) ; increased staining of insulin and preservation of islet ceils functions were more obvious in the STZ + ALA-pretreated rats. Conclusions ALA exerted its protective effect through reducing the oxidative stress and preserving pancreatic beta-cell integrity.