【摘要】 目的:探讨一氧化氮(NO)对肾缺血再灌注(ischem ia-reperfusion in jury,I-R I)时大鼠肾小球超微结构及负电荷位点的影响。方法:SD大鼠15只,建立肾缺血再灌注模型,动物随机分为5组:(1)假手术(sham)组(n=6);(2)I-R I组(n=6),缺血前20 m in舌静脉注入生理盐水0.3 mL;(3)SNP+I-R I组(n=6),缺血前20 m in舌静脉注入2.5μg/kg硝普钠(SNP);(4)AG+I-R I组(n=6),缺血前20 m in舌静脉注入10 mg/kg氨基胍(AG);(5)L-NNA+I-R I组(n=6),缺血前20 m in舌静脉注入10 mg/kg L-硝基精氨酸(L-NNA)。以聚乙烯亚胺(PEI)为阳离子探针标记肾小球滤过膜负电荷位点,透射电镜观察肾I-R I对大鼠肾小球超微结构及负电荷位点的影响。结果:(1)sham组电镜下见肾小球结构正常,肾小球基底膜(GBM)外透明层负电荷位点(AS)清晰,呈连续的规则点线状排列[(19.3±1.7)个/1 000 nm]。I-R I组肾小球足细胞足突有明显的融合现象;GBM外透明层AS排列稀疏[(16.6±1.0)个/1 000 nm,P<0.05],PEI颗粒小。(2)与I-R I组相比,给予SNP使肾I-R I大鼠肾小球滤过膜上皮细胞足突融合现象加重,肾小球GBM的AS[(11.7±3.2)个/1 000 nm]显著少于假手术组(P<0.05),且PEI颗粒的电子致密度也明显低于假手术组;而AG的应用使I-R I大鼠肾小球滤过膜损伤减轻,可见清晰的足突间隙;L-NNA+I-R I组大鼠肾小球上皮细胞足突融合也明显加重,但和I-R I组相比,L-NNA+I-R I组大鼠GBM的AS数量[(14.7±0.9)个/1 000 nm]无显著差异(P>0.05)。结论:肾I-R I时出现肾小球上皮细胞足突融合、肾小球滤过膜的负电荷位点减少等病理性损伤,NO可加重这些损伤;肾I-R I时肾小球滤过膜超微结构的损伤与NO的生成及其作用有关。更多还原

【Abstract】 AIM: To investigate the effects of nitric oxide on ultrastructure and anionic sites of glomerular in renal ischemia reperfusion injured(I-RI) rats.METHODS: Animals were divided randomly into five groups:(1) sham group(n=6);(2) I-RI group(n=6),0.3 mL normal saline was injected via venae lingualis 20 min before ischemia;(3) SNP+I-RI group(n=6),2.5 μg/kg sodium nitroprusside(SNP) was injected via venae lingualis 20 min before ischemia;(4) AG+I-RI group(n=6),10 mg/kg aminoguanidine(AG) was injected via venae lingualis 20 min before ischemia;(5) L-NNA+I-RI group(n=6),10 mg/kg N~ω-nitro-L-arginine(L-NNA) was injected via venae lingualis 20 min before ischemia.Anionic sites of glomerular were studied with a cationic probe-polyethyleneimine(PEI) and ultrastructure was observed under electron microscope in renal I-RI rats.RESULTS:(1) Ultrastructure of glomerular was normal and anionic sites(AS) was located clearly in lamina rare externa of GBM in sham rats.The PEI particles arranged regularly in line(19.3±1.7/(1 000 nm)) under electronic microscope.Obvious foot processes derangement and effacement were observed and the AS number in GBM of I-RI group was fewer(16.6±1.0/(1 000 nm),P<0.05) and the particle was smaller than that in sham group.(2) Compared with I-RI group,the foot process effacement was aggravated in SNP+I-RI group and L-NNA+I-RI group.SNP caused the numbers of anionic sites reduced after renal I-RI(11.7±3.2/(1 000 nm),P<0.05),and the electronic density of the PEI granule was also reduced.AG lead a increase in anionic site number(17.8±1.0/(1 000 nm,) P<0.05),but still fewer than that in sham group(P<0.05).The numbers of anionic sites was not changed in L-NNA+I-RI group(14.7±0.9/(1 000 nm),P>0.05).CONCLUSION: Foot process effacement and reduction of anionic sites were present in glomerular filtration membrane in renal I-RI rats.NO aggravated those injuries,indicating that NO plays a role in the ultrastructure damages of glomerular filtration membrane in I-RI rats.更多还原