目的研究氢氯噻嗪和吲哒帕胺对肥厚心肌及心肌中内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)表达的影响,从而探讨其逆转心肌肥厚可能的分子机制。方法15只成年♀SHR随机分为对照组、氢氯噻嗪组、吲哒帕胺组。治疗前、开始至结束时每周测血压1次。4wk后处死动物,取左心室称重后,计算左心室重与体重的比值,采用天狼猩红染色分析心肌间质和血管壁胶原分布。采用Western Blot法检测心肌eNOS蛋白质表达。结果治疗组动物收缩压及左心室重与体重比均明显低于对照组。心肌经天狼猩红染色后见治疗组心肌结构基本正常,与对照组相比未见明显的胶原沉积。并且治疗组在蛋白质水平上调心肌eNOS的表达(P〈0.05)。结论吲哒帕胺或氧氯噻嗪可逆转自发性高血压大鼠(spontaneous hypertensive rats.SHR)左室肥厚、改善心肌纤维化从而起到保护心脏的作用,可能与其促进心肌中eNOS的表达有关。
Aim To investigate effects of hydrochlorothiazide and indapamide on cardiac remodeling and expression of endothelial nitric oxide synthase (eNOS) in spontaneous hypertensive rats (SHR). Methods Fifteen female SHRs were randomly divided into 3 groups( n = 5 ) : control, hydrochlorothiazide ( HCTZ 10 mg · kg^- 1 · d^-1 ) and indapamide ( IND, 0. 625 mg · kg· ^-1 · d^-1 ) group. Systolic blood pressure (SBP) of the rats in each group was measured at pretreatment and each week. Four weeks later, rats were sacrificed and the ratio of heart weight to body weight was calculated, collagen deposition in the heart was determined by histochemistry with sirius red staining, and eNOS protein, expression of the heart was determined byWestern blot. Results Both HCTZ and IND reduced SBP of SHRs significantly(P 〈 0. 05 ) . The drug group showed normal myocardium structure as compared with control rats which showed myocardium cell hypertrophy, derangement, interstitial proliferation and mass collagen deposition. Additionally, HCTZ and IND increased the eNOS expression. Conclusion Both HCTZ and IND protects the heart by reversing cardiac remodeling, upregulating eNOS expression and reducing collagen deposition.