P-选择素和一氧化氮酶在大鼠肾脏缺血预处理中的表达

Expression of P-selectin and eNOS expression in rat renal ischemic precondiontioning

目的观察缺血预处理对肾脏缺血再灌注的保护作用及对P-选择素和一氧化氮酶(eNOS)表达的影响。方法先建立大鼠肾脏缺血模型,随机分为假手术组(S组),缺血再灌注组(IR组),预处理组(IPC组)。于再灌注24h观察各组实验大鼠血肌酐(Scr)、尿素氮(BUN)、丙二醛(MDA)和超氧化物歧化酶(SOD)的变化;并观察光镜下肾脏组织学改变,同时免疫组化检查肾脏细胞P-选择素和一氧化氮酶的表达水平。结果血Scr、BUN、MDA:IPC组明显低于IR组(P<0.05)。血SOD:IPC组明显高于IR组(P<0.05)。形态学:IR组可见大量肾小管坏死,超微结构多呈不可逆性改变。IPC组肾小管坏死较少,超微结构多为可逆性改变。P-selectin:IPC组肾脏P-selectin表达水平低于IR组。eNOS:IPC组肾脏eNOS表达水平明显高于IR组。结论缺血预处理减轻肾脏缺血/再灌注的病理损害,维持肾脏SOD活力,减少MDA含量的机制很可能是降低P-selectin和增加eNOS在肾脏的表达。

[Objective] To observe protective effects of ischemic precondiontionging and P-selectin and eNOS expression in renal isehcmial/ reperfusion injury model. [Methods] Rat model of ischemia was made by left renal artery occlusion. The rats were divided into three groups randomly： Sham-operated group （group S）, ischemia-reperfusion group （group IR）, ischemic preeondiontionging （group IPC）. The left renal underwent 60-minutes ischemie and 24 hours reperfusion. The levels of Scr, BUN, Superoxide Dismutase （SOD） and Malondialdehyde （MDA） in each group were examined. In addition, Pathological changes were also examined by light microscope. P-seleetin and eNOS expressions in kidney were tested by immunohistochemistry. [Results] Ser, BUN and MDA：The values in group IPC were significantly lower than that in group IR （P 〈0.05）. Blood SOD： The values in group IPC were significantly higher than that in group IR（P 〈0.05）. Morphology： In group IR patch necrosis of renal tubules and the ultrastructural damages seen on electoscopy were irreversible.Whereas,in group IPC scattered necrosis of renal tubules could be seen and the most of uhrastructural damages were reversible. P-selectin： The expression of P-selectin in group IPC was lower than that in group IR. eNOS： The expression of eNOS in group IPC was higher than that in group IR. [Conclusion] Ischemic precondiontionging could protect kidney from ischemia/reperfusion injury via scavenging oxygen free radicals ,improve the SOD＇ s activity in the kidney , reducing the levels of MDA in the kidneys. The mechanism might be that the herbs inhibit the expression of P - seleetin and increase eNOS in the kidneys.