肾血管性高血压大鼠心脏功能及心脏组织中ACE及AT1的mRNA和蛋白表达的性别差异

Gender difference of cardiac function and the ACE and AT1 mRNA and protein expression in heart tissue of renovascular hypertensive rats

目的观察肾血管性高血压大鼠心脏功能及心脏组织中血管紧张素转化酶(ACE)及AT1的mRNA和蛋白表达的性别差异.方法75只SD大鼠采用两肾一夹(2K1C)法建立肾血管性高血压大鼠模型,并将其中25只雌性大鼠通过切除双侧卵巢制备雌激素低下的肾血管性高血压模型.75只SD大鼠共分为3组,即雄性2K1C组(2K1C-M组)、雌性2K1C组(2K1C-F组)、雌性去势手术组(2K1C-OVX组),每组25只.于32周时测体重行心脏血流动力学检查后,迅速取出心脏,用生理盐水冲洗后液氮冻存,留取部分左心室心肌组织标本,用免疫印迹检测蛋白表达,RT-PCR检测组织中相关分子的mRNA表达.结果血流动力学结果显示,2K1C-OVX组的收缩压明显低于2K1C-F组,差异有统计学意义(P<0.05).2K1C-OVX组室内压最大下降速率明显高于2K1C-F组,差异有统计学意义(P<0.05).RT-PCR的结果显示,2K1C-M组的ACE1、AT1a、AT1b的mRNA表达量高于2K1C-F组和2K1C-OVX组,而ACE2的mRNA表达量低于2K1C-F组和2K1C-OVX组,差异均有统计学意义(均P<0.05).在蛋白表达方面,2K1C-M组的AT1蛋白表达量高于2K1C-F组和2K1C-OVX组,而ACE2蛋白表达量低于2K1C-F组,差异均有统计学意义(均P<0.05).结论肾血管性高血压大鼠心脏功能及心脏组织中ACE1及AT1的mRNA和蛋白的表达存在性别差异.

Objective To investigate gender difference of cardiac function and the angiotensin converting enzyme(ACE)and AT1 mRNA and protein expression in heart tissue of renovascular hypertensive rats.Methods The renovascular hypertensive rat model was established in 75 SD rats by two-kidney one-clip(2K1C)method and 25 female rats among them were prepared with low estrogen renovascular hypertensive model by removing bilateral ovaries.A total of 75 SD rats were divided into three groups,namely,male 2K1C group(2K1C-M group),female 2K1C group(2K1C-F group),and female ovariectomized group(2K1C-OVX group),with 25 rats in each group.At 32 weeks,weight was measured and cardiac hemodynamics was performed and then the heart was quickly taken out,rinsed with normal saline and frozen in liquid nitrogen.Part of the left ventricular myocardial tissue specimens were left,protein expression was detected by Western blot,and mRNA expression of relevant molecules in the tissue was detected by RT-PCR.Results The hemodynamic results showed that the systolic blood pressure of the 2K1C-OVX group was significantly lower than that of the 2K1C-F group,and the difference was statistically significant(P<0.05).The maximum indoor pressure drop rate in the 2K1C-OVX group was significantly higher than that in the 2K1C-F group,and the difference was statistically significant(P<0.05).RT-PCR results showed that ACE1,AT1a and AT1b mRNA expression levels of the 2K1C-M group were higher than those of the 2K1C-F group and 2K1C-OVX group,while ACE2 mRNA expression level was lower than that of the 2K1C-F group and 2K1C-OVX group,with statistically significant differences(all P<0.05).In terms of protein expression,the AT1 protein expression level in the 2K1C-M group was higher than that in the 2K1C-F group and 2K1C-OVX group,while ACE2 protein expression level was lower than that in the 2K1C-F group,with statistically significant difference(all P<0.05).Conclusion The cardiac function,mRNA and protein expressions of ACE1 and AT1 in cardiac tissue show gender difference in renovascular hypertensive rats.