臭氧后处理对大鼠肾脏缺血/再灌注后Smad-7表达的影响

目的探讨臭氧后处理对大鼠肾脏缺血/再灌注损伤(IRI)后Smad-7表达的影响。方法采用随机数字表法将24只SD大鼠分为3组,假手术组(n=8)、缺血/再灌注组(n=8)和臭氧后处理组(n=8)。假手术组的大鼠在切除右肾后即缝合腹壁;缺血/再灌注组的大鼠用无创伤血管夹夹闭左肾动、静脉45 min后开放血管夹进行再灌注;臭氧后处理组:再灌注后10 d内,每日对大鼠经直肠吹入氧气和臭氧的混合气体2.5³.0 mL[臭氧浓度为50 mg/L,0.5 mg/(kg·d)],余同缺血/再灌注组。全自动生化分析仪检测大鼠血清肌酐和尿素氮,组织病理学检查观察大鼠肾组织的病理情况改变,蛋白免疫印迹法检测各组大鼠Smad-7的表达变化。结果臭氧后处理的血清尿素氮、肌酐值显著低于缺血再灌注组[(19.36±7.24)mmol/L vs(31.63±13.14)mmol/L、(79.27±19.93)μmol/L vs(151.36±27.26)μmol/L,P<0.05]且臭氧后处理组的肾组织病理学改变较缺血/再灌注组轻,仅部分刷状缘消失、部分管腔明显扩张、偶见管型。蛋白免疫印迹实验结果显示,与假手术组相比,IRI组Smad-7的表达量明显降低,而臭氧后处理可以明显上调Smad-7的表达,差异有统计学意义(P<0.05)。结论臭氧后处理可能通过上调Smad-7的表达而发挥肾脏保护作用。

Effect of Ozone Postconditioning on Expression of Smad-7 in Renal Ischemia and Reperfusion Injury in Rats

Objective To investigate the effect of ozone postconditioning （OP） on the expression of Smad-7 in rats after renal ischemia and reperfusion injury （IRI）. Methods Twenty-four SD rats were randomly divided into three groups：sham operation group, IRI group and OP group,8 rats in each group. In sham operation group, the right kidneys of rats were excised and then the abdomen walls were sutured. In IRI group,with no wound vascular clamp, left renal arteries and veins of rats were clamped for 45 min, then vascular clamp was opened and the rats got reperfusion. In OP group, the operation steps were the same as the IRI group, but within 10 d after surgery, the renal OP was induced by rectal insufflation of oxygen and ozone 2.5-3.0 mL[ ozone 50 mg/L,0.5 mg/（ kg · d）, once everyday]. The parameters（ blood urea nitrogen and creatine） of renal function were tested by auto-biochemical analyzer. The changes of renal tissue were examined by a microscope. The expression of Smad-7 was detected by Western blot. Results Compared with sham operation group,BUN and Cr were significantly increased in IRI group, however, these targets in OP group were significantly decreased compared with those in group IRI[ （ 19.36±7.24） mmol/L vs（31.63 ± 13.14） mmol/L, （79.27 ± 19.93 ） μmol/L vs（ 151.36 ± 27.26） μmol/L,P 〈 0.05 ]. The pathological change of renal tissue in IRI group was more significant than that in OP group,only part of the brush border disappeared, part of the lumen was obviously dialated, and occasional tube type was seen. Western blot showed that the expression of Smad-7 decreased in IRI group compared with sham group, but OP could signif- icantly up-regulate the expression of Smad-7 compared with IRI group,with statistically significant difference （ P 〈 0.05 ）. Conclusion OP may execute its renal protective effects through up-regulating the expression of Smad-7.