自发性高血压大鼠心脏和肾脏血管紧张素转换酶2和血管紧张素转换酶的表达

Expression of angiotensin converting enzyme 2/ angiotensin converting enzyme mRNA and protein in myocardium and nephors in spontaneously hypertensive rats

目的观察不同月龄的自发性高血压大鼠（SHR）的心脏和。肾脏血管紧张素转换酶2（ACE2）和血管紧张素转换酶（ACE）的mRNA和蛋白质表达水平，探讨ACE2／ACE与血压状态的内在联系。方法12周龄雄性自发性高血压大鼠（spontaneously hypertensive rat，SHR）18只和12周龄WKY大鼠（Wistar-Kyoto rats，WKY）18只。随机分为SHR组和WKY组，每组抽取各9只，处死进行与喂养12周后处死的24周龄大鼠相同的研究内容。采用实时定量RT-PCR法（Real-time Quantitative RT-PCR）检测ACE2、ACE mRNA（messenger ribonucleic acid，mRNA）的表达，免疫组织化学检测ACE2、ACE等蛋白的表达。结果（1）与同周龄WKY组比较，SHR组的血压显著增加（P均〈0．01），心脏和肾脏的ACE2 mRNA表达显著降低（P均〈0．01），ACE mRNA表达显著升高（P〈0．05，P〈0．01）；与12周龄SHR组比较，24周龄SHR的血压亦显著增加（P〈0．01），ACE2 mRNA表达显著降低（P均〈0．01），ACE mRNA表达显著升高（P均〈0．01）。（2）与同周龄的WKY组比较，SHR组心脏和肾脏的ACE2免疫染色表达显著减少，ACE免疫染色表达显著增多。结论 心脏和肾脏的ACE2／ACE mRNA表达与血压升高相关。

Objective To investigate the relationship between the expressions of angiotensin converting enzyme 2 （ACE2）/ACE mRNA in myocardium-nephors and the blood pressure in spontaneously hypertensive rats （SHR）. Method A total of 18 male of 12 weeks old SHRs and 18 male of 12 weeks old Wistar Kyoto（WKY） rats were got for the experimental study. Nine SHRs and 9 WKY rats were randomly taken out as controls and sacrificed for detecting the mRNA expressions and protein of ACE2 and ACE. Other halves of rats of both groups were fed for 12 weeks and then sacrificed for detecting of the same biomarkers as in controls. The mRNA expressions of ACE2 and ACE were determined by real-time quantitative RT-PCR. The protein level of ACE2 and ACE were determined by immunohistochemistry. Results Systolic blood pressure （SBP） in SHRs of 12 and 24 weeks old increased compared with that in WKY （ all P 〈 0.01 ）. SBP in SHRs of 24 weeks old increased compared with that in SHRs of 12 weeks old （ P 〈 0.01）. The cardiac and renal expressions of ACE2 mRNA in SHRs of 12 and 24 weeks old were all significantly lower than those in WKY rats （ P 〈 0.01 ）. The expressions of ACE mRNA in SHRs of 12 and 24 weeks old were all significantly higher than those in WKY rats （ P 〈 0.05, P 〈 0.01 ）. The cardiac and renal expression of ACE2 mRNA in SHRs of 24 weeks old was significantly lower than that in SHRs of 12 weeks （P 〈 0.01 ）. The myocardtial and renal expression of ACE mRNA in SHRs of 24 weeks old was significantly higher than that in 12 SHRs of weeks old （ P 〈 0.01 ）. The positive reactions of ACE2 protein found in kidney displayed in brown colur. The ACE2 proetin appeared in uniform distribution of brown granules in WKY rats and comparatively scanty distribution of brown granule in SHRs. Conclusions There are correaltions between the expressions of ACE2/ACE mRNA as well as protein and blood pressure.