Turcani M, Jacob R
Institute of Pathophysiology, Medical School, Comenius University, Bratislava, Slovak Republic.
Can J Physiol Pharmacol. 1998 Jun;76(6):613-20. doi: 10.1139/cjpp-76-6-613.
To test the ability of the heart to express characteristic geometric features of concentric and eccentric hypertrophy concurrently, constriction of the ascending aorta was performed in 4-week-old rats. Simultaneously, these rats were treated with an arteriolar dilator minoxidil. An examination 6 weeks after induction of the hemodynamic overload revealed no signs of congestion in systemic or pulmonary circulation in rats with aortic constriction or minoxidil-treated sham-operated rats. The magnitude of hemodynamic overload caused by aortic constriction or minoxidil treatment could be considered as equivalent, because the same enlargement of left ventricular pressure-volume area was necessary to compensate for either pressure or volume overload. Myocardial contractility decreased in rats with aortic constriction, and the compensation was achieved wholly by the marked concentric hypertrophy. Volume overload in minoxidil-treated rats was compensated partially by the eccentric hypertrophy and partially by the increased myocardial contractility. In contrast, increased lung weight and pleural effusion were found in all minoxidil-treated rats with aortic constriction. Unfavorable changes in left ventricular mass and geometry, relatively high chamber stiffness, and depressed ventricular and myocardial function were responsible for the massive pulmonary congestion.
为了测试心脏同时表达向心性和离心性肥大特征性几何特征的能力，对4周龄大鼠进行升主动脉缩窄。同时，用小动脉扩张剂米诺地尔治疗这些大鼠。诱导血流动力学超负荷6周后检查发现，主动脉缩窄大鼠或米诺地尔治疗的假手术大鼠的体循环或肺循环均无充血迹象。主动脉缩窄或米诺地尔治疗引起的血流动力学超负荷程度可视为相当，因为左心室压力-容积面积的相同增大对于补偿压力或容量超负荷都是必要的。主动脉缩窄大鼠的心肌收缩力下降，完全通过明显的向心性肥大实现代偿。米诺地尔治疗大鼠的容量超负荷部分通过离心性肥大、部分通过心肌收缩力增加得到代偿。相比之下，在所有接受米诺地尔治疗的主动脉缩窄大鼠中均发现肺重量增加和胸腔积液。左心室质量和几何形状的不利变化、相对较高的心室僵硬度以及心室和心肌功能的降低是导致大量肺充血的原因。
