茶多酚对肾缺血再灌注损伤大鼠血清超氧化物歧化酶和丙二醛的影响

目的:探讨茶多酚(TP)对缺血再灌注损伤大鼠肾脏的保护作用及其机制。方法:健康雄性SD大鼠42只,均切除右侧肾脏,随机分为假手术组、肾脏缺血再灌注损伤(ischemia reperfusion injury,IRI)组(左侧肾蒂用无创动脉夹夹闭1h恢复血液灌注)、TP预处理组(在实验前1周给予TP200mg/kg灌胃)。肾脏IRI组及TP预处理组在左肾缺血1h恢复再灌注0、2、24h后分别检测血清肌酐(Scr)、血清丙二醛(MDA)水平及血清超氧化物岐化酶(SOD)活性,观察肾组织的病理变化,并对3组进行比较。结果:TP预处理组肾组织病理变化轻于肾脏IRI组,其肾小管以肿胀为主,个别呈现坏死样改变,肾间质水肿、充血、炎性细胞浸润不明显,IRI组肾小管上皮细胞变性坏死,上皮细胞脱落,肾小管管腔变窄,肾间质水肿、充血伴炎性细胞大量浸润。与假手术组比较,在不同时间点肾脏IRI组的Scr、MDA水平明显升高(P<0.05),SOD活性明显降低(P<0.05)。TP预处理组的Scr、MDA水平均较肾脏IRI组明显降低(P<0.05),而SOD活性明显增强((P<0.05)。结论:TP在肾脏IRI过程中,通过增强SOD活性,清除过多的氧自由基,减少MDA的生成起到对肾脏的保护作用。

Impact of tea polyphenols on serum superoxide dismutase and malondialdehyde in renal ischemia reperfusion rat

Objective:To explore the protective effects and its mechanism of tea polyphenols on renal ischemia reperfusion injury in rats models. Methods: Fourty-two SD male rats were randomly divided into 3 groups: sham-operated group, renal ischemia reperfusion injury (IRI) groups (non-invasive artery folder clap the left renal pedicle one hour then reperfusion) and tea polyphenols precondiontioning groups (TP 200 mg/kg gavage before one week). The levels of serum creatinine (Scr), malondialdehyde (MDA) and activity of serum superoxide dismutase (SOD) in each group were respectively detected after renal ischemia reperfusion for 0 h, 2 h and 24 h, Pathological changes were also examined by light microscope. Results: Renal pathological lesions of tea polyphenols preconditioning group reduced significantly compared with renal IRI group (P<0.05), renal interstitial edema, hyperemia, inflammatory cell infiltration were not obvious. Degeneration and necrosis of renal tubular epithelial cells, epithelial cells shed, narrowed tubular, renal interstitial edema, congestion and massive infiltration of inflammatory cells in renal IRI group. the level of Scr, MDA decreased significantly (P<0.05) while the activity of SOD improved significantly (P<0.05) in renal IRI group compare with false groups at different time points, tea polyphenols preconditioning improved the activity of SOD significantly (P<0.05),decreased the level of Scr, MDA significantly (P<0.05), comparing with renal IRI groups at different time points. Conclusion: Tea polyphenols could protect the kidney from renal ischemia reperfusion injury by enhancing the activity of SOD and remove excess oxygen free radicals reducing the generation of MDA.