摘要
背景:醛固酮是左心室肥厚的主要致病因子,有效抑制其生物合成可防治高血压左室肥厚。目的:观察丹参酮ⅡA对自发性高血压大鼠心肌醛固酮合成及其相关基因CYP11B1和CYP11B2表达的作用,以及其抑制高血压左室肥厚的可能途径。设计:以自发性高血压大鼠为实验对象,以正常血压的WKY大鼠为对照,完全分组设计,随机对照实验,各组间均数的比较用方差分析。单位:华中科技大学同济医学院附属同济医院急诊科和中西医结合研究所。材料:实验于2003-01/2004-02在华中科技大学同济医学院附属同济医院急诊科实验室完成。选用12周龄雄性正常血压WKY大鼠10只为对照组,将12周龄雄性自发性高血压大鼠20只随机分为2组,每组10只,分别为高血压组和丹参酮ⅡA组。方法:丹参酮ⅡA组经腹腔每天注射1.5mg/kg丹参酮ⅡA,高血压组和对照组均腹腔注射相当容积的蒸馏水。实验12周后断头处死大鼠留取心肌标本,心肌组织醛固酮和血管紧张素II含量采用放射免疫法测定,心肌醛固酮合成相关基因CYP11B1和CYP11B2mRNA表达水平采用反转录聚合酶链反应检测。主要观察指标:实验12周后各组大鼠心肌组织醛固酮和血管紧张素II含量及CYP11B1和CYP11B2基因的mRNA表达量比较。结果:自发性高血压大鼠20只和正常血压WKY大鼠10只均进入结果分析。①实验12周后大鼠心肌组织醛固酮含量:高血压组和丹参酮ⅡA组均明显高于对照组[(0.056±0.014),(0.031±0.010),(0.018±0.009)ng/g,P<0.01,0.05],丹参酮ⅡA组明显低于高血压组(P<0.05)。②实验12周后大鼠心肌组织血管紧张素II含量:高血压组和丹参酮ⅡA组均明显高于对照组[(0.093±0.016),(0.088±0.024),(0.043±0.012)ng/L,P<0.01]。③实验12周后大鼠心肌组织CYP11B1基因的表达量:高血压组和丹参酮ⅡA组均明显高于对照组(2.774±0.138,2.533±0.127,1.973±0.102,P<0.05)。④实验12周后大鼠心肌组织CYP11B2基因的表达量:高血压组和丹参酮ⅡA组均明显高于对照组(1.573±0.106,1.024±0.113,0.786±0.121,P<0.01,0.05),丹参酮ⅡA组明显低于高血压组(P<0.05)。⑤各组大鼠心肌组织CYP11B1和CYP11B2及参照基因甘油醛-3-磷酸脱氢酶基因的反转录聚合酶链反应产物电泳带的位置与理论值相符。结论:丹参酮ⅡA抑制高血压左室肥厚的效应可能与其下调心肌醛固酮合成相关基因CYP11B2的表达水平,减少心脏局部醛固酮的生物合成有关。
BACKGROUND:Aldosterone is main pathogenic factor of left ventricular hypertrophy, for which, to inhibit its biosynthesis effectively may prevent and treat hypertension induced by left ventricular hypertrophy. OBJECTIVE: To investigate the effects of TanshinoneⅡA on myocardiac aldosterone synthesis and expression of its relevant genic CYP11B1and CYP11B2 in spontaneously hypertensive rats(SHR) and explore the possible mechanism of TanshinoneⅡA on inhibiting hypertension induced by left ventricular hypertrophy. DESIGN:SHR were employed as the objects in the experiment and WKY rats with normal blood pressure (WKY rats) were employed in the controlgroup. Complete group division and randomized control experiment was designed. Analysis of variance was used for the means comparison among groups. SETTING:Department of Emergency and Institute of Integrated Traditional Chinese and Western Medicine in Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology. MATERIALS:The experiment was performed in the laboratory of Department of Emergency in Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from January 2003 to February 2004, in which, 10 male WKY rats with normal blood pressure of 12-week-old were employed in the control group and 20 male SHR of 12-week-old were randomized into two groups, named hypertension group and Tanshinone ⅡA group, 10 rats each group. METHODS:In Tanshinone ⅡA group, TanshinoneⅡA 1.5 mg/kg was injected abdominally everyday. The distilled water of same volume was injected abdominally in hypertension group and the control group. Twelve weeks after experiment, myocardial specimens were collected after rats sacrificed. Radioimmunoassay was used to determine the contents of aldosteron and angiotensin II in myocardial tissue and reverse transcriptase polymerase chain reaction (RT-PCR) were used to measure mRNA level of CYP11B1 and CYP11B2 genes relevant to aldosterone synthesis. MAIN OUTCOME MEASURES: Contents of aldosterone and angiotensin II in myocardial tissue and mRNA expression of CYP11B1 and CYP11B2 genes. RESULTS:All of 20 SHR and 10 WKY rats entered result analysis. ① Myocardial aldosterone content of rats in 12 weeks after experiment: that in hypertension group and Tanshinone II A group was higher remarkably than that in the control group [(0.056±0.014), (0.031±0.010), (0.018±0.009) ng/g, P < 0.01, 0.05]; that in Tanshione II A group was lower remarkably than that in the hypertension group (P < 0.05). ② Myocardial angiotension II content of rats in 12 weeks after experiment: that in the hypertension group and Tanshinone IIA group was higher remarkably than that in the control group [(0.093±0.016), (0.088±0.024), (0.043±0.012) ng/L, P < 0.01]. ③ Expression of CYP11B1 gene in myocardial tissue of rats in 12 weeks after experiment: that in the hypertension group and Tanshinone II A group was higher remarkably than that in the control group(2.774±0.138, 2.533 ±0.127, 1.973±0.102, P < 0.05). ④Expression of CYP11B2 gene in myocardial tissue of rats in 12 weeks after experiment: that in the hypertension group and Tanshinone IIA group was higher remarkably than that in the control group (1.573±0.106, 1.024±0.113, 0.786±0.121, P < 0.01, 0.05); that in the Tanshinone IIA group was lower remarkably than that in the hypertension group (P < 0.05). ⑤The electrophoresis band positions of myocardial CYP11B1 and CYP11B2 as well as RT-PCR products of glyceraldehydes-3-phosphate dehydrogenase (GAPDH), the consulting gene, were in conformity with the theoretic values. CONCLUSION:The inhibition of TanshinoneⅡA on hypertension induced by left ventricular hypertrophy is probably contributed to its down-regulating effect on myocardiac CYP11B2 gene expression relevant to aldosterone synthesis and to its reducing action on local biosynthesis of aldosterone in heart.
出处
《中国临床康复》
CSCD
北大核心
2005年第23期243-245,F003,共4页
Chinese Journal of Clinical Rehabilitation
基金
湖北省科技攻关资助项目(2003AA301C47)~~
