雷米普利抑制自发性高血压大鼠细胞凋亡研究

Investigation of Inhibitory Effect of Ramipril on Apoptosis in Spontaneously Hypertensive Rats

为了研究血管紧张素转化酶抑制剂对自发性高血压大鼠细胞凋亡的作用，对雄性高血压大鼠（ＳＨＲ），分别从３周龄和５周龄起按每日１ｍｇ／ｋｇ剂量，给予雷米普利口服治疗，至１０周龄时停药，第１６周龄时处死，并以年龄、性别配对的ＳＨＲ以及ＷＫＹ大鼠作对照。测定各组血压、心脏与体重比，并以定量ＤＮＡ末端最大标记量（Ｌｍａｘ）的ＴｄＴ法、电镜、原位ＤＮＡ末端标记技术（ＴＵＮＥＬ）和放射自显影分析ＤＮＡ梯形带的方法检测心肌细胞凋亡。结果显示：早期雷米普利治疗不仅能显著降低ＳＨＲ血压、心脏与体重比，而且能抑制ＳＨＲ年龄依赖性的细胞凋亡；ＳＨＲ治疗组典型的ＤＮＡ梯形带消失，ＴＵＮＥＬ标记产物明显减少，其Ｌｍａｘ与ＷＫＹ对照组比较无明显差别（Ｐ＞０．１），但较未治疗ＳＨＲ组减少７０．７％。上述结果表明，雷米普利能抑制ＳＨＲ高血压的形成和心肌肥厚，并可阻止高血压形成过程中产生的细胞凋亡。

To explore the effect of angiotensin converting enzyme (ACE) inhibitor on apoptosis in spontaneously hypertensive rats(SHR), and normotensive control rats (WKY) at different ages were used. Ramipril (1mg·kg -1 ·d -1 ) was administered orally to male SHR from 3 or 5 weeks to 10 weeks of age. Male and age matched untreated SHR and WKY were used as controls. Experiments determined. Apoptosis in cardiomyocytes of SHR was quantified by a maximal labeling (L max ) method and the characteristic features of apoptosis were identified by electron microscopy (EM), in situ labeling of DNA strand breaks with terminal deoxynucleotidyl transferase mediated dUTP end labeling (TUNEL) and autoradiographic analysis of DNA fragments. The results of the quantitative method showed an age dependent increase in apoptosis in the cardiac tissues of SHR. A significant increase in DNA breaks occurred as early as age 4 weeks and continued to increase up to a plateau at age 16 weeks in the cardiac tissue of SHR, whereas there was no significant change in apoptosis in WKY up to 64 weeks. Moreover, after the treatment of SHR with ramipril, an inhibitor of ACE, the DNA fragmentation, like BP and HW/BW, was reduced significantly (70.7%) as compared with that of untreated SHR( P <0 01); and similar to that of the WKY( P >0 1), the DNA ladder disappeared, which was very obvious in the untreated SHR.These studies demonstrate that ramipril can prevent the development of hypertension and myocardial hypertrophy and can inhibit the increase in the apoptosis of SHR cardiac myocytes, suggesting that apoptosis may be involved in the pathogenesis of genetic hypertension.