血清一氧化氮与肾小管上皮细胞Bax在肾缺血再灌注损伤大鼠中的表达及意义

Significances and Expressions of Serum Nitric Oxide and Bax in Renal Tubular Epithelia in Rats With Renal Ischemia Reperfusion

目的探讨血清一氧化氮(NO)的变化和肾小管上皮细胞Bax在大鼠肾缺血再灌注(IR)损伤中表达的意义。方法将Sprague-Dawley大鼠48只随机分为IR组(n=40,并根据IR时间,进一步分为IR 2h组,IR 6h组,IR 12h组,IR 24h组,IR 72h组,每组8只)和对照组(n=8)。用无损伤动脉夹钳夹大鼠双侧肾蒂45min制成肾IR损伤模型。对照组只暴露双肾,不钳夹肾蒂。观察IR后2h,6h,12h,24h和72h血清NO水平变化和以上各时间点肾小管上皮细胞Bax及细胞凋亡的改变。结果对照组血清NO水平较IR组低,IR 2h组NO水平开始升高[(90.470±10.222)μmol/L],IR 12h组达最高峰[(137.864±22.317)μmol/L],之后逐渐下降,IR 72h组尚未降至正常水平。IR 12h组血清NO水平与对照组比较,差异有统计学意义(P<0.01)。IR组血清肌酐(Scr)水平较对照组明显升高,以IR 12h组Scr水平达最高峰[(120.850±22.237)μmol/L],与对照组比较,差异有统计学意义(P<0.01)。对照组肾小管上皮细胞Bax(2.450±0.639)及细胞凋亡水平[(0.900±0.385)个/视野]较低,IR 2h后各值均逐渐升高[15.400±3.474,(8.725±1.313)个/视野],12h达峰值[69.025±6.550,(26.850±1.476)个/视野],IR 12h肾组织病理改变最严重。结论IR后,血清NO及肾小管上皮细胞Bax水平增高,诱导肾小管上皮细胞凋亡。

Objective To investigate the significance and expression of serum nitric oxide （NO） and Bax in renal tubular epithelia in rats with renal ischemia reperfusion （IR）. Methods Forty-eight male Sprague-Dawley rats were randomly divided into IR group （n= 40, further divided into IR 2 h group, IR 6 h group, IR 12 h group, IR 24 h group, IR 72 h group） and control group（n=8）. Every group consisted of 8 rats. The rats of renal IR injury exposed to 45 min bilateral renal pedicle clamping. Rats in control group were exposed and their renal pedicles were not clamped. The change tendency of serum NO and Bax in renal tubular epithelia at IR 2 h, IR 6 h, IR 12 h, IR 24 h and IR 72 h were observed. Results The level of serum NO of rats in control group [-（73. 980±8. 356） μmol/L] was lower than that in IR group, and the level of serum NO of rats in IR 12 h group was highest [,,（137. 864±22. 317） μmol/L], after that, the levels of serum NO were gradually decreased, and the level of serum NO of rats in IR 72 h group [（85. 071 ± 11. 204）μmol/L] still did not reduce to normal level. The levels of serum creatinine （Scr） of rats in IR groups were obviously increased as compared with that in control group [--（22. 775± 6. 508）μmol/L] than that of IR group. The level of Scr of rats in IR 12 h group was the highest [＇-（120. 850±22. 237） μmol/L]. The levels of Bax and apoptosis in renal tubular epithelia in rats in control group were lower [2. 450±0. 639, 0. 900±0. 385]. After IR 2 h, those were gradually increased, and the levels of Bax and apoptosis in renal tubular epithelia in IR 12 h group were the highest [69. 025±6. 550, 26. 850± 1. 476]. The pathological lesions of nephridial tissue were most severe at IR 12 h. Conclusions The expression of serum NO and Bax pro-apoptotic protein in renal tubular epithelia were unregulated after IR, and that induced apoptosis.