中文摘要：

目的：探讨高血压大鼠心肌肾素-血管紧张素系统（RAS）元件基因（ATNG、AT1R、AT2R）的昼夜节律表达与高血压左心室肥厚的相关性.方法：建立肾性高血压大鼠的模型.取自发性高血压大鼠（SHR）,肾性高血压大鼠（RHR）以及正常SD大鼠,在 12 h 光暗交替的环境中饲养2周后,每隔 4 h 取心脏,测心重指数等各项指标,用RT-PCR的方法检测高血压大鼠心肌组织与正常大鼠心肌组织中血管紧张素原（ATNG）,血管紧张素Ⅱ受体1型（AT1R）与血管紧张素Ⅱ受体2型（AT2R）表达的变化.结果：SHR和RHR的左心重与全心重比值及全心重与体重比值较对照组明显增大;SHR和RHR组心脏RAS元件基因表达较对照组增高.RAS元件基因的mRNA的表达都表现出昼夜节律,SHR和RHR组昼夜变化的幅度较对照组明显.结论：RAS元件基因的过表达和其波动的增加在心肌肥厚的发病过程中可能起到了一定的作用.

英文摘要：

AIM： To investigate whether the circadian mRNA expression of the renin-angiotensin system （RAS） components （ ATNG, AT1 R, AT2 R ） in myoeardium is correlated with left ventrieular hypertrophy in both spontaneously hypertensive rats （SHR） and renal hypertensive rats （RHR）. METHODS： The model of RHR was established using 2K1C （two-kidney one elip）. SHR, RHR, and normotensive eontrol rats （CON） were housed in a separate environment-eontrolled room for two weeks, in which a strict 12-hour light/12-hour dark cycle regimen was enforced （lights on at 9 ： 00, zeitgeber time [ZT0] ）. Rats were killed every 4 hours from 9 ： 00 am （ZT0） to 5 ： 00 pm （ZT20） on three separate days. We examined the circadian mRNA expression of ATNG, AT1 R, AT2 R in the hearts of SHR, RHR and CON rats by RT-PCR. RESULTS： Heart weight to body weight ratios and left ventricle weight to heart weight ratios indicated a significant increase in SHR and RHR compared with normotensive rats. The cardiac mRNA expression of the RAS components showed circadian oscillations in SHR, RHR and CON rats. The amplitudes of these circadian fluctuations were greater in the SHR and RHR than in the CON rats. The mRNA levels of the RAS components were increased in the SHR and RHR compared with the CON rats at many time points. CONCLUSION： The data indicate that overexpression and enhanced amplitudes of circadian fluctuations of RAS components in SHR and RHR may play a role in the development of left ventricular hypertrophy.