目的:观察芝麻素对自发性高血压大鼠(SHR)心肌细胞凋亡的影响。方法:SHR大鼠随机分为SHR组、芝麻素高、低剂量组及卡托普利组,每组6只,另取WKY大鼠6只作为正常对照组。各治疗组分别灌胃给予相应药物14周。TUNEL染色法观察大鼠心肌细胞凋亡水平,Western blot法检测心肌组织Bax、Bcl-2蛋白表达水平,比色法检测血清乳酸脱氢酶(LDH)活性、心肌组织总抗氧化能力(TAOC)及丙二醛(MDA)含量。结果:与SHR组相比,各治疗组心肌细胞凋亡明显少(P〈0.05或P〈0.01),心肌组织Bax蛋白表达水平明显下调,Bcl-2蛋白表达水平明显升高。同时,各治疗组大鼠心肌组织MDA含量明显下降,T-AOC显著升高(P〈0.05或P〈0.01)。结论:芝麻素可显著减少自发性高血压大鼠心肌细胞凋亡,其机制与增强机体抗氧化能力、调节Bcl-2和Bax蛋白表达平衡有关。
Objective: To observe the protective effect of sesamin on cardiomyocyte apoptosis in spontaneously hypertensive rats and the possible mechanism involved. Methods: Twenty -four spontaneously hypertensive rats (SHR) were randomly divided into SHR group, low dose sesamin group, high dose sesamin group and captopril group. Other 6 Wistar- Kyoto rats were used as the control group. Rats in sesanfin and captopril groups were given intragastrieally corresponding drugs for 14 weeks. Cardiomyocyte apoptosis was evaluated by TUNEL assay. Protein expressions of Bax and Bcl -2 were determined by western blot. Levels of serum activity of lactate dehydrogenase (LDH) and total antioxidant capacity (TAOC) and malondialdehyde (MDA) in cardiac tissue were determined by colorimetric assays. Results: Supplementation with sesamin significantly reduced cardiomyocyte apoptosis in SHR, with protein expression of Bax down - regulation and Bcl- 2 up -regulation markedly. In addition, sesamin effectively reduced serum level of LDH activity and enhanced T- AOC in cardiac tissue, while MDA content was reduced obviously( P 〈 0.05 or P 〈 0.01 ). Conclusion: Sesamin can suppress cardiomyocyte apoptosis in spontaneously hypertensive rats, of which the potential mechanism may be associated with the enhancement of antioxidant capacity and the regulation of the balance between Bcl -2 and Bax protein.