nNOS/NO对5/6肾切除大鼠肾小球硬化的影响

目的:本研究观察5/6肾切除大鼠肾组织nNOS、NO表达的变化,探讨nNOS、NO对肾小球硬化的影响。方法:48只健康雄性SD大鼠随机分为2组,模型组(M组,n=24):行5/6肾切除术;假手术组(S组,n=24):手术方式同模型组,仅行麻醉暴露双肾,剥除肾包膜,不做手术切除。分别于实验第4、8、12周每组各随机抽取4只大鼠处死,观察不同时间点以下指标:(1)血清尿素氮、肌酐和24h尿蛋白定量;(2)HE、Masson染色光镜下观察肾脏组织形态改变,并进行肾小球硬化半定量分析;(3)免疫组化方法检测肾组织神经型一氧化氮合酶(nNOS)的表达;(4)比色法检测血清NO的浓度。结果:(1)与同期假手术组相比,模型组大鼠血清尿素氮、肌酐及24h尿蛋白均显著升高(P<0.01),提示手术成功;(2)与同期假手术组相比,模型组大鼠肾小球硬化指数均升高(P<0.05);(3)免疫组化提示nNOS主要定位在肾皮质的致密斑,5/6肾切除组大鼠nNOS水平呈持续性下降,手术后4周起模型组nNOS表达与假手术组的差异有统计学意义,模型组nNOS水平与肾小球硬化提示存在直线负相关(P<0.05);(4)5/6肾切除后NO水平呈持续下降趋势,与假手术组的差异有统计学意义,模型组血清NO水平与肾小球硬化提示存在直线负相关(P<0.05)。结论:5/6肾切除后伴随肾小球硬化的进展存在nNOS、NO表达的减少,提示nNOS/NO途径参与了肾小球硬化病变的过程。

Effect of nNOS/NO on glomerular sclerosis rats with 5/6 nephrectomy

Objective: To investigated the effect of nNOS/NO expression on glomerular sclerosis rats with 5/6 nephrectomy.Methods:A total of 48 health male SD rats were randomly divided into two groups: model group(n=24),with 5/6 nephrectomy,and Sham-operation group(n=24).Under anesthesia,exposed bilateral renal capsule were striped without resection.Four rats were randomly sacrificed in each group at 4th,8th,12th weeks,respectively,and the following indexes were observed: Serum urea nitrogen,serum creatinine and 24h quantitative urine protein.Change of the renal tissue was observed by HE and Masson dyeing under light-microscopy.Quantitative analysis of glomerular sclerosis indexes was also performed.The expression of nNOS of renal tissues was detected by immunohistochemical method,and the concentrations of NO in serum by colorimetric method.Results:Compared with the sham-operation group,the level of serum urea nitrogen,creatinine and 24 h urine protein increased significantly in model rats,indicating successful surgery(P<0.01).The glomerular sclerosis indexes were increased in model rats(P<0.05).Immunohistochemical assay showed nNOS main located in macula densa of the cortex by,and the nNOS level was continuously declined after 5/6 nephrectomy.The difference in nNOS expression between model group and sham-operation group was statistically significant,and there was negative correlation between the nNOS level and glomerular sclerosis indexes in model group(P<0.05).The NO level was decreased after 5/6 nephrectomy consistently,with significant difference between model group and sham-operation group.There was negative correlation between NO level and glomerular sclerosis indexes in model group(P<0.05).Conclusions:The nNOS/ NO expression were decreased after 5/6 nephrectomy as the progress of the glomerular sclerosis,suggesting that the reduce of nNOS/NO involved in the progress of glomerular sclerosis.