促红细胞生成素对脂多糖所致大鼠肾脏损伤的保护作用

目的利用脂多糖（LPS）建立大鼠内毒素血症导致肾脏损伤模型,探讨促红细胞生成素（EPO）对肾脏损伤的保护作用及可能机制,为防治内毒素引起的肾脏损伤提供依据。方法将40只成年Wistar大鼠随机分成空白对照组、EPO对照组、LPS组和LPS＋EPO组。LPS组和LPS＋EPO组大鼠尾静脉注射LPS（10 mg/kg）建立肾脏损伤模型,对照组给予同等量生理盐水,30 min后,EPO对照组和LPS＋EPO组给予rh EPO（5 000 U/kg）经尾静脉注射。其余两组大鼠给予生理盐水。在LPS注射后的6 h和24 h每组分别处死5只大鼠,生化分析仪测定大鼠血清尿素氮（BUN）和肌酐（Cr）水平,放射免疫方法测定大鼠血清肿瘤坏死因子-α（TNF-α）水平。注射后24 h处死大鼠制备肾组织切片,HE染色后光镜下观察大鼠肾脏病理结构改变,透射电子显微镜观察大鼠肾脏超微结构改变。应用免疫印记方法检测大鼠肾脏丙氨酸氨基转移酶（AKT）、磷酸化丙氨酸氨基转移酶（p-AKT）以及核因子-κB（NF-κB）表达水平。结果与对照组比较,LPS组和LPS＋EPO组大鼠血清BUN、Cr和TNF-α水平升高（P均〈0.05）;LPS组以上3个指标升高程度显著高于LPS＋EPO组（P均〈0.05）。与对照组比较,LPS组p-AKT和p-AKT/AKT表达增强（p-AKTP=0.000、p-AKT/AKTP=0.000）、NF-κB表达增强（P=0.012）;与LPS组比较,LPS＋EPO组p-AKT和p-AKT/AKT表达下降（p-AKTP=0.002、p-AKT/AKTP=0.005）,NF-κB表达下降（P=0.066）。光镜下LPS组肾小管上皮细胞坏死、间质水肿和淋巴细胞浸润;LPS＋EPO组亦可见间质水肿和淋巴细胞浸润,但较LPS组减轻。电镜下LPS组肾小管上皮细胞空泡化,线粒体固缩和内皮细胞增生;LPS＋EPO组肾小球滤过膜增厚,远曲小管上皮细胞内线粒体轻度肿胀和溶酶体增多,损伤较LPS组减轻。结论 EPO可通过减轻炎症反应、减轻组织损伤有效的保护LPS导致的肾损伤,其机制可能与磷脂酰肌醇3-激酶?

Protective effects of erythropoietin on lipopolysaccharide-induced kidney injuries in rats

Objective To investigate the protective effect of erythropoietin（EPO） on kidney injuries and the possible mechanisms in rats with kidney injury induced by lipopolysaccharide（LPS）. Methods Total of 40 adult Wistar rats were randomly divided into four experimental groups： blank control group, EPO control group, LPS group and（LPS ＋ EPO） group. Rats model of kidney injury were established by tail vein injection of LPS for 10 mg/kg in LPS group and（LPS ＋ EPO） group, while the control groups received the same amount of saline. Thirty minutes later, recombinant human EPO treatment（5 000 U/kg） was administered by tail vein injection in（LPS ＋ EPO） group and EPO control group, while saline was administered in the other two groups. Six hours and 24 hours after LPS challenge, the changes of blood urea nitrogen（BUN） and creatinine（Cr） were evaluated by biochemical analysis and the levels of tumor necrosis factor-α（TNF-α） were determined by immunoradioassay. Twenty-four hours after the treatment, histological examination of tissue sections was carried out by hematoxylin and eosin staining, while ultrastructure evaluation of organ tissues was assessed by transmission electron microscopy. The expression levels of alanine aminotransferase assav（AKT）, phosphorylation of alanine aminotransferase assav（p-AKT） and nuclear factor-кB（NF-κB） were detected by Western blot. Results Compared with the control group, the serum BUN, Cr and TNF-α levels of rats in LPS group and（LPS ＋ EPO） group were elevated（P〈0.05）; among which the above three index in LPS group increased significantly than that in（LPS ＋ EPO） group（P〈0.05）. Compared with the control group, the levels of p-AKT and p-AKT/AKT expression enhanced in LPS group（p-AKTP = 0.000, p-AKT/AKTP = 0.000）, while NF-κB expression increased（P = 0.012）. Compared with LPS group, the levels of p-AKT and p-AKT/AKT expression decreased in（LPS ＋ EPO） group（p-AKTP = 0.002, p-AKT/AKTP = 0.005）, whi