Dong Jing, Chen Xiaoping, So Yanling, Xin Hongbo, Jiang Wei, Jiang Lingyun
Department of Cardiology, West China Hospital, Sichuan University, Chengdu 610041, China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2009 Oct;26(5):1082-7.
This experiment on rats was aimed to investigate the expression of intermedin (IMD) in hypertrophic cardiac myoctye of renal vascular hypertension induced by incomplete ligation of the left renal artery, and so to detect and compare the changes of the expression after administration of Valsartan, Amlodipine and Enalapril respectively. The criterion for standard modeling was systolic pressure > or = 140 mmHg. At 4 weeks after successful modeling, 60 SD male rats were randomly divided into 5 groups, namely the hypertrophy group, the 3 drug-treatment groups, and the sham-operation group as control. Blood pressure, left ventricular mass index (LVMI), and the left ventricular mean transverse diameter of myocardial cell (LVTDM) were investigated at the 10th week after model establishment. Gene expression of IMD mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR), and the optical density of the band was measured by use of the Gel Documentation System. The ratio of IMD mRNA to beta-actin mRNA was considered the relative amount of IMD. When compared with control, the blood pressure increased significantly in the hypertrophy group. There was no statistically significant difference between the treatment groups. No significant difference in heart rate was noted at 4 weeks after operation in all groups. LVMI and LVTDM levels were significantly higher in the hypertrophy group than in the other groups; LVMI and LVTDM levels showed no significant difference among the treatment groups but they were obviously higher than those of the Sham-operation group. The gene expression of IMD mRNA in the hypertrophy group was upregulated in the myocardium, when compared with that in the other groups. Meanwhile, although IMD mRNA in the treament groups was higher than that in the Sham-operation group, no statistically significant difference of myocardial IMD mRNA was found between the treament groups. These results suggested that, in this experiment, intracardiac IMD mRNA was upregulated and could participate in the regulation of cardiac remodeling in renal vascular hypertension-induced cardiac hypertrophy. This upregulation could improve the pathologic and physiologic process of cardiac hypertrophy, and could associate with the pressure loading or myocardia hypertrophy. However, the change did not display any difference that could be attributed to the variety of hypotensive drugs.
本大鼠实验旨在研究中介素（IMD）在左肾动脉不完全结扎所致肾血管性高血压肥大心肌细胞中的表达，并检测和比较分别给予缬沙坦、氨氯地平和依那普利后其表达的变化。标准建模标准为收缩压≥140 mmHg。成功建模4周后，将60只SD雄性大鼠随机分为5组，即肥大组、3个药物治疗组和作为对照的假手术组。在模型建立后第10周，检测血压、左心室质量指数（LVMI）和心肌细胞左心室平均横径（LVTDM）。采用逆转录-聚合酶链反应（RT-PCR）检测IMD mRNA的基因表达，并使用凝胶成像系统测量条带的光密度。IMD mRNA与β-肌动蛋白mRNA的比值被视为IMD的相对含量。与对照组相比，肥大组血压显著升高。各治疗组之间无统计学显著差异。术后4周时，所有组心率均无显著差异。肥大组LVMI和LVTDM水平显著高于其他组；各治疗组LVMI和LVTDM水平无显著差异，但明显高于假手术组。与其他组相比，肥大组心肌中IMD mRNA的基因表达上调。同时，虽然治疗组的IMD mRNA高于假手术组，但各治疗组之间心肌IMD mRNA无统计学显著差异。这些结果表明，在本实验中，心脏内IMD mRNA上调，可参与肾血管性高血压所致心肌肥大的心脏重塑调节。这种上调可改善心肌肥大的病理生理过程，并可能与压力负荷或心肌肥大有关。然而，这种变化并未显示出因降压药物种类不同而产生的差异。
