芝麻素和维生素E通过调节内皮型一氧化氮合酶和NAD(P)H氧化酶4改善D-半乳糖和三氯化铝诱导的大鼠主动脉内皮功能障碍

Sesamin and vitamin E ameliorate aortic endothelial dysfunction rats induced by D-galactose and aluminum trichloride via regula⁃tion of endothelial nitric oxide synthase and NAD(P)H oxidase 4

目的观察芝麻素(Ses)和维生素E(Vit E)联用对D-半乳糖(D-gal)和三氯化铝(AlCl_(3))致大鼠主动脉内皮功能障碍的保护作用,并探讨其可能机制。方法大鼠ip给予D-ga(l180 mg·kg^(-1))+ig给予AlCl_(3)(15 mg·kg^(-1))连续84 d,建立大鼠主动脉内皮功能障碍模型。将模型大鼠随机分为模型组、模型+VitE10 mg·kg^(-1)组、模型+Ses 160 mg·kg^(-1)组和模型+Ses 160 mg·kg^(-1)+Vit E 10 mg·kg^(-1)组,同时设正常对照组。连续给药70 d后,尾袖法测量大鼠的收缩压(SBP)、舒张压(DBP)和平均压(MBP)。戊巴比妥钠(30 mg·kg^(-1),ip)麻醉后,取胸主动脉制备2段3 mm动脉环,离体灌流法观察主动脉环对乙酰胆碱(ACh)和硝普钠的舒张反应。HE染色观察主动脉病理变化;化学比色法测定血清总抗氧化能力(T-AOC)、过氧化氢(H_(2)O_(2))和一氧化氮(NO)含量;免疫组化法观察主动脉内皮型一氧化氮合酶(eNOS)蛋白表达。Western印迹法观察主动脉eNOS和NAD(P)H氧化酶4(NOX4)蛋白表达。结果与模型组比较,模型+Ses+Vit E组离体主动脉对ACh(1×10^(-7)~1×10^(-4)mol·L^(-1))的舒张反应显著升高(P<0.01);模型+Ses和模型+Vit E组的SBP、DBP和MBP降低(P<0.01)、血清T-AOC和NO含量升高(P<0.01)、H_(2)O_(2)含量降低(P<0.01)、主动脉eNOS表达增加(P<0.01)及NOX4表达减少(P<0.01)。与模型+Ses比较,模型+Ses+Vit E组SBP、DBP和MBP均降低(P<0.01或P<0.05)、NO含量升高(P<0.01)和H_(2)O_(2)含量降低(P<0.01)、主动脉eNOS蛋白表达增加(P<0.01),NOX4蛋白表达降低(P<0.05)。与模型+Vit E组比较,模型+Ses+Vit E组血清T-AOC和NO含量升高(P<0.01)、H_(2)O_(2)含量降低(P<0.01)、主动脉eNOS蛋白表达增加(P<0.01),NOX4表达降低(P<0.01)。结论联用Ses和Vit E通过上调eNOS和下调NOX4蛋白表达,改善D-gal和AlCl_(3)诱导的大鼠主动脉内皮功能障碍。

OBJECTIVE To observe the protective effect of sesamin(Ses)and vitamin E(Vit E)against aortic endothelial dysfunction in rats induced by D-galactose(D-gal)and aluminum trichloride(AlCl_(3)),and explore its conceivable mechanisms.METHODS A model of aortic endothelial dysfunction rats was established by D-gal(180 mg·kg^(-1),ip)combined with AlCl_(3)(15 mg·kg^(-1),ig)for 84 d.Model rats were randomly divided into model,model+Vit E 10 mg·kg^(-1),model+Ses 160 mg·kg^(-1),and model+Ses 160 mg·kg^(-1)+Vit E 10 mg·kg^(-1) groups.After 70 d of treatment with Ses and Vit E,systolic blood pressure(SBP),diastolic blood pressure(DBP)and mean blood pressure(MBP)were measured by tail cuff.The rats were anesthetized by sodium pentobarbital(30 mg·kg^(-1),ip).Thoracic aortas from the rats were removed and divided into two parts(3 mm in length).The relaxation of the aortic ring induced by acetylcholine(ACh)and sodium nitroprusside was measured.The primary pathologic changes in the aorta were observed by HE staining.Total antioxidant capacity(T-AOC),hydrogen peroxide(H_(2)O_(2))and nitric oxide(NO)in serum were measured by colorimetric analysis.The expression of endothelial nitric oxide synthase(eNOS)positive cells in the aorta were measured by immunohistochemistry.The expres⁃sions of eNOS and NAD(P)H oxidase 4(NOX4)protein in the aortal were detected by Western blotting.RESULTS Compared with the model group,the relaxation response with increase in ACh concentra⁃tion(1×10^(-7)-1×10^(-4) mol·L^(-1))was enhanced(P<0.01)in model+Ses+Vit E,SBP,DBP and MBP decreased(P<0.01),the serum T-AOC and NO level were increased(P<0.01),the serum H_(2)O_(2) levels were reduced(P<0.01),the eNOS expression was increased(P<0.01)and NOX4 expression was reduced(P<0.01)in each treatment group.Compared with model+Ses,the SBP,DBP and MBP were lower(P<0.01 or P<0.05),the serum H_(2)O_(2) level was lower(P<0.01),the serum NO level was increased(P<0.05),the eNOS expression level was higher(P<0.01)and the NOX4 expression level was reduced(P<0.05)in model+Ses+Vit E.Compared with the model+Vit E,the serum T-AOC and NO levels were increased(P<0.05),the serum H_(2)O_(2) level was lower(P<0.01),eNOS expression was increased(P<0.01)and NOX4 expression was reduced(P<0.05)in model+Ses+Vit E group.CONCLUSION Ses and Vit E can ameliorate aortic endothelial dysfunction of rats induced by D-gal and AlCl_(3) via the regulation of eNOS and NOX4.