冬虫夏草对自发性高血压大鼠klotho表达及氧化应激的影响

Effects of cordyceps sinensis on renal klotho expression and oxidative stress in spontaneously hypertensive rats

目的:观察冬虫夏草干预治疗后自发性高血压大鼠(SHR)肾脏klotho表达和氧化应激的变化,探讨其在治疗高血压肾损伤中的作用机制。方法:15只22周龄雄性SHR随机分为模型组(SHR组)、冬虫夏草组[5g/(kg·d)]、氯沙坦组[50mg/(kg·d)],以5只22周龄雄性Wistar-Kyoto(WKY)大鼠为正常对照。8周后测定尾动脉收缩压、24h尿蛋白量、尿N-乙酰-8-D-氨基葡萄糖苷酶(NAG酶)、血尿素氮(BUN)及血肌酐(SCr)等,并观察肾脏病理改变;分别用RT-PCR、免疫组化法及Western Blot检测肾脏klotho mRNA及蛋白表达;检测肾脏总抗氧化能力(T-AOC)、丙二醛(MDA)、铜锌超氧化物歧化酶(Cu/Zn-SOD)、锰超氧化物歧化酶(Mn-SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)水平。结果:模型组大鼠肾脏出现高血压肾损伤的病理改变。经冬虫夏草或氯沙坦干预后,肾脏病理损害减轻,24h尿蛋白量、尿NAG酶、BUN及SCr降低;肾脏klotho表达上调;MDA含量降低,T-AOC、Cu/Zn-SOD、CAT及GSH-Px活性增加(与模型组比较,P<0.05或P<0.01),Mn-SOD无明显改变(P>0.05)。结论:klotho基因表达异常及氧化应激参与了高血压肾损伤的发病过程;冬虫夏草可上调klotho表达和抑制氧化应激反应,这可能是其对高血压肾损伤起保护作用的机制之一。

Objective： We investigated the effects of cordyceps sinensis （CS） on renal klotho expression and oxidative stress in spontaneously hypertensive rats （SHR） in order to study the therapeutic mechanism of CS in hypertensive renal damage. Methodology： Fifteen 22-week-old male SHR were divided into three groups by the means of random number table （each of five rats）：model （SHR） group, CS group [5 g/（kg-d） ], Losartan （Los） group [50 mg/（kg＇d）]. Five 22-week-old male Wistar-Kyoto （WKY） rats were regarded as tile control group. After 8 weeks, 24 hours urinary protein （Upro） ,urinary N-acetyl-13-D-glucosaminidase （NAGase）, blood urea nitrogen （BUN） and serum creatinine （SCr） were measured ; renal pathological changes were viewed under light microscopy by HE and Masson staining ; the mRNA and protein expression of klotho in kidney were determined by RT-PCR, immunohistochemical staining and Western Blot respectively ; the levels of total antioxidant capacity （T-AOC）, malondialdehyde （ MDA ）, Cu/Zn superoxide dismutase （ Cu/Zn-SOD）, Mn superoxide dismutase （ Mn-SOD）, catalase （CAT） and glutathione peroxidase （GSH-Px） were evaluated. Results： The pathological characteristics of hypertensive renal damage were showed in the kidney of SHR group. After treatment with CS or losartan, the renal pathological damage was ameliorated, the levels of Upro, urinary NAGase, BUN and SCr were lower than SHR group; as well as klotho expression was up-regulated; the content of MDA was decreased, the activities of T-AOC, Cu/Zn-SOD, CAT and GSH-Px were increased （compared with SHR group,P 〈0. 05 or P 〈0. 01 ）. There was no apparent change in level of Mn-SOD between four groups （ P 〉 0. 05）. Conclusion： Abnormal expression of klotho gene and oxidative stress play an important role in pathogenesis of hypertensive renal damage. CS can up-regulate klotho expression and resist oxidative stress, which may be one of the protective mechanisms in hypertensive renal damage.