低分子肝素对缺血再灌注大鼠的肾保护作用

The protection of low molecular heparin therapy on rat renal ischemia reperfusion injury:An experimental study

目的探讨低分子量肝素(LMWH)通过调节血浆促炎细胞因子与抗炎细胞因子的表达水平,对肾缺血再灌注(IRI)大鼠的肾保护作用。方法建立大鼠IRI模型,将健康Wistar大鼠80只随机分为正常对照组、假手术组、模型未治疗组、LMWH治疗组,同时按术后观察时间再分为1、3、6、24h四组。检测各组血清肌酐(Scr)、尿素氮(BUN)、血清肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、白介素-4(IL-4)及白介素-10(IL-10)水平;并同步采用流式细胞术观测中性粒细胞(PMNs)细胞间粘附分子-1(ICAM-1)浓度表达的变化。结果①肾缺血再灌注后,大鼠血清抗炎性细胞因子IL-4、IL-10浓度降低,而血清促炎细胞因子(TNF-α、IL-6)浓度及ICAM-1表达水平较假手术组明显增加,且三者升高的峰值时点相似;经相关分析发现,ICAM-1与IL-6间呈现显著正相关,而IL-6又与TNFα存在着良好的相关性;②LMWH治疗后TNF-α、IL-6浓度降低,而IL-4、IL-10浓度升高;PMNs对ICAM-1的表达较模型未治疗组显著减少(P<0.05)。结论①IRI可引起大鼠促炎性细胞因子水平增高,通过活化ICAM-1,介导白细胞与肾小管上皮细胞的粘附级联免疫反应,导致急性肾损伤;②LMWH可调节促炎性细胞因子和抗炎性细胞因子浓度的相对平衡状态,抑制ICAM-1的表达,有利于重建机体免疫系统的内稳状态,保护肾功能。

Objective To approach the protection on rat renal ischemia reperfusion injury through regulating plasma levels of proinflammatory cytokines and antiinflammatory cytokines by low molecular weight heparin. Methods The model for rat renal ischemia reperfusion injury was established, 80 healthy Wistar rats were equally randomized into following groups： the blank control group, sham- operated control group, IR1 control group and LMWH treatment group.Meanwhile,4 groups were stratified according to the postoperative observation periods （1h,3h,6h and 24h）.Levels of serum creatinine （Scr）, blood urea nitrogen （BUN）, tumor necrosis factor-alpha（TNF-α）,intedeukin-6（IL-6）,intedeukin-4（IL-4）and interleukin-10 （IL-10） were tested respectively in each group. Flow cytometry was used to examine the variation of intercellular adhesion molecular-I （ICAM-1） of polymorphonuclear neutrophils （PMNs）. Results （l）Afier reperfusion, plasma levels of IL-4, 1L-10 were reduced, and levels of TNF-α, 1L-6, 1CAM-I were significantly increased when compared with that of the sham-operated control group. The three increase spots of peak value were similar to each other. Correlation analysis showed that there was a significant positive correlation between 1CAM-I and IL-6.And also 1L-6 correlated with TNFα. （2）After LMWH treatment, plasma levels of TNF-α, IL-6 were declined while IL--4, IL-10 rised. The expressions of ICAM-1 in PMNs were significantly decreased when compared with that of the IRI control group （P〈 0.05）, Conclusions （1）IRI may cause the increase of proinflammatory cytokine in rat plasma, activate 1CAM-1 to coordinate immunoreaction between leucocyte and renal tubular epithelial cell, and lead to AKI; （2）LMWH may accommodate levels of proinflammatory cytokines and antiinflammatory cytokines to keep the equilibrium state, inhibit the expression of ICAM-1, and benefit for rebuilding the steady state of immune system to protect the renal function.