糖尿病大鼠肾组织核因子κB活性与血管紧张素系统的关系(英文)

Association between activity of nuclear factor-kappa B and angiotensin system in renal tissues of diabetic rats

背景:目前已知血管紧张素Ⅱ在糖尿病肾病发病中起重要作用。因此,核因子κB对糖尿病大鼠肾组织血管紧张素系统可能有调节作用。目的:观察抑制核因子κB活性与糖尿病大鼠肾组织血管紧张素Ⅱ及其1型受体mRNA表达的关系。设计:完全随机分组设计,对照实验。材料:实验于2000-03/04在中山医科大学实验动物中心完成。选用51只纯种清洁级雄性Wistar大鼠。方法:①对其中39只大鼠进行造模,采用链脲佐菌素溶于枸橼酸缓冲液穴0.1mmol/L,pH=4.5雪,按60mg/kg腹腔内注射,制备糖尿病模型,空腹血糖维持在13.9mmol/L以上则模型制备成功。随机将造模后39只大鼠分为3组:模型组穴n=17,未给予其他干预措施,正常饲养雪和吡咯烷二硫基甲酸酯(核因子κB活性抑制剂)干预组眼n=22,腹腔内注射吡咯烷二硫基甲酸酯(剂量20mg/kg),2次/d演。其余12只为正常对照组,未造成糖尿病模型,正常饲养。②各组饲养18周后取出肾脏,电泳迁移率变动分析技术检测核因子κB活性,采用反转录聚合酶链反应法检测血管紧张素Ⅱ1型受体mRNA表达,采用放射免疫分析法检测血管紧张素Ⅰ与血管紧张素Ⅱ含量。37℃水浴后的血管紧张素Ⅰ水平减去4℃检测的血管紧张素Ⅰ水平则为肾素活性。③计量资料差异性比较采用单因素方差分析,非正态分布资料经正态转换后再作统计学处理。主要观察指标:各组大鼠肾组织血管紧张素Ⅰ,Ⅱ含量和肾素、核因子κB活性及血管紧张素Ⅱ1型受体mRNA表达比较。结果:正常对照组、模型组、吡咯烷二硫基甲酸酯干预组大鼠各脱失1,6,13只,进入结果分析11,11,9只。①核因子κB活性:模型组明显高于正常对照组和吡咯烷二硫基甲酸酯干预组(P<0.01),正常对照组与吡咯烷二硫基甲酸酯干预组相近。②肾组织肾素活性:3组相近。③肾组织血管紧张素Ⅰ含量:模型组明显高于正常对照组和吡咯烷二硫基甲酸酯组(P<0.01)。④肾组织血管紧张素Ⅱ含量:模型组与正常对照组相近,吡咯烷二硫基甲酸酯组明显低于模型组和正常对照组(P<0.01)。血管紧张素Ⅱ1型受体mRNA表达:模型组明显低于正常对照组(P<0.01);吡咯烷二硫基甲酸酯组明显低于模型组和正常对照组(P<0.01)。结论:糖尿病大鼠肾组织核因子κB活性增加,抑制核因子κB活性后可导致糖尿病大鼠肾组织血管紧张素Ⅱ水平及血管紧张素Ⅱ1型受体mRNA表达下降。

BACKGROUND： Nowadays, angiotensin Ⅱ plays an important role in onset of diabetic nephropathy. Therefore, the nuclear factor-KB may have adjustive effects on angiotonin system of kidney tissue of diabetic rats. OBJECTIVE： To observe the relationship of activity of inhibitive nuclear factor-κB with angiotensin Ⅱ and its type 1 receptor mRNA expression of renal tissue of diabetic rats. DESIGN： Completely randomized group design, control experiment. MATERIALS： The experiment was conducted at the Experimental Animal Center, Sun Yat-sen University of Medical sciences between March and April 2000. Fifty-one pure breed clean grade male Wistar rats were selected. METHODS： ①Models were established in 39 rats. Streptozotocin dissolving in citric acid buffer （0.1 mmol/L,pH=4.5） were given to establish diabetic models with 60 mg/kg intraperitoneal injection. If the fasting blood glucose maintained above 13.9 mmol/L, the establishment of models was successful. The thirty-nine rats were randomly assigned into 3 groups： model group （n=17, without other interventional measure, feeding normally） and pyrrolidine dithiocar2, bamate （PDTC） （active inhibitor of nuclear factor-κB） interventional group [n=22, PDTC at the dose of 20 mg/kg were given with intraperitoneal injection, twice a day]. Other 12 rats were as normal control group, did not make into diabetic models with normal breeding. ②After feeding for 18 weeks kidneys were got in every group. The activity of nuclear factor-κB was detected with electrophoretic mobility shift assay. The expression of type 1 receptor mRNA of angiotensin Ⅱ was measured with reverse transcription polymerase chain reaction （RT-PCR）. Contents of angiotonin Ⅰ and angiotensin Ⅱ were tested with Radio Immunoassay （RIA）. Activity of rennin was referred to that the result of the level of angiotonin Ⅰ at 37 ℃ water bath subdnced to that at 4 ℃. ③Difference of measurement data was compared with single factor analysis of variance. After normal transformation, the non-normal distribution data were conducted with statistical disposal. MAIN OUTCOME MEASURES： Comparison of contents of angiotcnsin 1 and Ⅱ, activities of rennin and nuclear factor-κB and expression.of type 1 receptor mRNA of angiotensin Ⅱ in renal tissues of rats of each group. RESULTS： In the normal control group, model group and PDTC interventional group 1, 6 and 13 rats were dropped out, respectively, so 11, 11 and 9 rats in each group were involved in the result analysis. ①Activity of nuclear factor-κB： It was higher significantly in the model group than that in the normal control group and PDTC interventional group （P 〈 0.01 ）. It was similar between the normal control group and the PDTC interventional group. ②Activity of rennin of renal tissue： It was similar among the 3 groups. ③Content of angiotonin Ⅰ of renal tissue： It was higher obviously in the model group that that in the normal control group and the PDTC intcrventional group （P 〈 0.01 ）. ④Content of angiotensin Ⅱ in renal tissue： It was similar between the model group and the normal control group. It was lower markedly in the PDTC interventional group than that in the model group and the normal control group （P 〈 0.01 ）. Expression of type 1 receptor mRNA of angiotensin Ⅱ ： It was lower remarkably in the model group than that in the normal control group （P 〈 0.01 ）. It was lower distinctly in the PDTC interventional group than that in the model group and the normal control group （P 〈 0.01 ）. CONCLUSION： The increase of activity of nuclear factor-κB in renal tissue of diabetic rats can inhibit the activity of nuclear factor-κB, which will induce the reduction of the level of angiotensin Ⅱ and expression of type 1 receptor mRNA of angiotensin Ⅱ in renal tissue of diabetic rats.