厄贝沙坦对STZ致糖尿病前期小鼠胰岛β细凋亡及氧化应激的影响

发布时间：2018-03-23 11:05

本文选题：胰岛β细胞　切入点：凋亡　出处：《广西医科大学》2015年硕士论文

【摘要】：研究目的：通过建立糖尿病前期小鼠胰岛p细胞凋亡模型,研究厄贝沙坦对胰岛p细胞凋亡及氧化应激的影响,明晰其介导细胞凋亡和氧化应激通路中的角色扮演。研究方法： (1)糖尿病前期小鼠胰岛p细胞凋亡模型的建立：选取雄性BABL/C小鼠,分别予60mg/kg、80mg/kg、100mg/kg小剂量STZ腹腔注射,观察时点分别为干预后6h、12h和24h,监测血糖、胰腺HE染色以Tunel检测胰岛p细胞凋亡率。 (2)厄贝沙坦+STZ组：300mg/kg厄贝沙坦灌胃一周后予腹腔注射80mg/kg STZ; STZ组：腹腔注射80mg/kg STZ;正常对照组：无任何干预。行HE染色、免疫组织化学、Tunel检测,采用real-timePCR检测AT1R、Caspase-3、P38MAPK、ROS及NADPH mRNA表达。研究结果： (1)糖尿病前期小鼠胰岛β细胞凋亡模型的建立：在所有测试时点血糖均在6-11mmol/L范围内波动,未达到糖尿病模型范畴。与对照组相比,实验组各时点的胰岛p细胞凋亡率均明显升高(P0.05)；各实验组均在12h时点凋亡率达到最高峰,并且80mg/kg组与60mg/kg、100mg/kg相比明显升高(P0.05)。 (2)厄贝沙坦对糖尿病前期小鼠胰岛p细胞凋亡机制的研究：与对照组比较,厄贝沙坦+STZ组及STZ组血糖、凋亡率均明显升高(P0.000),但血糖水平10mmol/L。与STZ组相比,厄贝沙坦+STZ组胰岛p细胞凋亡率明显下降(P0.001)。厄贝沙坦+STZ组胰岛素的表达量较STZ组有所上升(P0.001)。在STZ组,胰腺组织中AT1R、Caspase-3 mRNA及氧化应激相关指标P38MAPK, ROS和NADPH mRNA表达增加(P0.05)。经过厄贝沙坦干预后,各指标mRNA的表达均呈下调趋势(P0.05)。结论： (1)单次小剂量STZ诱导的小鼠胰岛p细胞凋亡在STZ注射后12h出现凋亡高峰。在本研究中80mg/kg浓度的STZ在12h的胰岛p细胞凋亡率最高,提示建模成功。 (2)经过厄贝沙坦灌胃预处理后再予注射STZ可以降低胰岛p细胞凋亡率。注射STZ后可以引起小鼠胰岛细胞AT1R表达升高,引起胰岛细胞凋亡损伤可能与RAS系统激活有关。STZ可以引起胰岛细胞氧化应激水平的升高和细胞凋亡的增加,而厄贝沙坦早期干预通过降低P38MAPK、Caspase-3和ROS、NADPH的表达,有效降低氧化应激和细胞凋亡而达到保护胰岛细胞的作用。
[Abstract]:Objective: to study the effects of irbesartan on pancreatic islet p cell apoptosis and oxidative stress by establishing a model of islet p cell apoptosis in prediabetic mice. Methods: to establish a model of pancreatic islet p cell apoptosis in prediabetic mice: male BABL/C mice were injected intraperitoneally with 60 mg / kg 80 mg / kg / kg 100 mg / kg STZ, respectively. The observed time points were 12 h and 24 h after intervention, respectively, and blood glucose was monitored. Pancreatic HE staining was used to detect the apoptosis rate of pancreatic islet p cells by Tunel. (2) Irbesartan STZ group (1: 300 mg / kg irbesartan) was intraperitoneally injected with 80mg/kg STZ one week after gavage; STZ group was intraperitoneally injected with 80mg/kg STZ; normal control group was treated with HE staining without any intervention. Immunohistochemical Tunel assay and real-timePCR were used to detect the expression of AT1RnCaspase-3p38MAPKROS and NADPH mRNA. Results: 1) Establishment of islet 尾 cell apoptosis model in prediabetic mice: blood glucose fluctuated in the range of 6-11mmol/L at all test points. Compared with the control group, the apoptotic rate of pancreatic islet p cells in the experimental group was significantly higher than that in the control group, and the apoptotic rate reached the peak at 12 h in each experimental group. In addition, compared with 60 mg / kg 100 mg / kg 80mg/kg group, the mechanism of irbesartan on apoptosis of islet p cells in prediabetic mice was significantly higher than that in 60 mg / kg / kg 80mg/kg group. Compared with the control group, the blood glucose of irbesartan STZ group and STZ group was significantly higher than that of the control group. The apoptotic rate was significantly increased, but the blood glucose level was 10 mmol / L. Compared with the STZ group, the apoptotic rate of islet p cells in irbesartan STZ group was significantly lower than that in the STZ group. The expression of insulin in irbesartan STZ group was higher than that in STZ group. In STZ group, the expression of insulin in irbesartan STZ group was significantly higher than that in STZ group. The expression of Caspase-3 mRNA and P38 MAPK, ROS and NADPH mRNA in pancreatic tissue increased after irbesartan intervention. The expression of mRNA was down-regulated (P 0.05). Conclusion: the apoptosis of islet p cells induced by a single low dose of STZ reached a peak at 12 h after STZ injection. In this study, the apoptotic rate of islet p cells was the highest at the concentration of 80mg/kg at 12 h. It was suggested that the model was successfully established. (2) injection of STZ after irbesartan intragastric preconditioning could reduce the apoptosis rate of islet p cells and increase the expression of AT1R in islet cells of mice after injection of STZ. The apoptosis injury of islet cells may be related to the activation of RAS system. STZ may induce the increase of oxidative stress and apoptosis of pancreatic islet cells, and the early intervention of irbesartan can reduce the expression of P38 MAPKCaspase-3 and Rosna DPH. The protective effect of islet cells was achieved by reducing oxidative stress and apoptosis.
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R587.2

【参考文献】