Tomanek R J, Whitaker M T
Department of Anatomy, University of Iowa, Iowa City 52242.
Cardiovasc Res. 1990 Mar;24(3):204-9. doi: 10.1093/cvr/24.3.204.
The aim of the study was to compare the compensatory nature of left ventricular hypertrophy in models of normal and increased peripheral resistance.
Peak left ventricular performance was compared in normotensive Wistar Kyoto (WKY) rats, in a subset of this strain with biventricular hypertrophy associated with volume overload (WKY-CH), and in spontaneously hypertensive rats (SHR), all studied at one year of age (ie, long term hypertrophy).
8 WKY-CH rats with biventricular hypertrophy were compared with 8 WKY (normal right and left ventricular weights). These groups were then compared with 9 SHR rats. All were maintained under identical conditions.
Left ventricular to body weight ratios (mg:g) were as follows: WKY-CH 2.78(SEM 0.09); SHR 2.90(0.09); WKY 2.10(0.09). Systolic blood pressures (mm Hg) were normal in WKY-CH [104(9)] and WKY [111(9)], but raised in SHR [163(8)]. Left ventricles from WKY and WKY-CH had normal histology and no fibre disorientation, fibrosis, or other morphological abnormalities. Peak cardiac index (ml.min-1.body weight-1) measured during rapid volume expansion with Tyrode's solution was higher in WKY-CH [427(33)] than in WKY [315(33)] and SHR [349(31)] (p less than 0.05). When peak stroke volume was expressed per mg left ventricular weight there were no significant differences between the groups. Peripheral resistance (mean arterial pressure divided by cardiac output) at peak cardiac output was higher in SHR [1.20(0.12)] than in either WKY-CH [0.57(0.08)] or WKY [0.74(0.08)].
These data show that both types of hypertrophy enhance peak left ventricular performance. In WKY-CH, which have normal peripheral resistance, the larger ventricle allows a higher peak cardiac index compared to WKY with no left ventricular hypertrophy. In SHR, the higher left ventricular mass is used to overcome an increased peripheral resistance and thereby provide a normal peak cardiac index.
本研究旨在比较正常外周阻力模型和外周阻力增加模型中左心室肥厚的代偿性质。
比较正常血压的Wistar Kyoto（WKY）大鼠、该品系中一部分伴有容量负荷过重所致双心室肥厚的大鼠（WKY-CH）以及自发性高血压大鼠（SHR）的左心室峰值功能，所有大鼠均在1岁时进行研究（即长期肥厚）。
将8只患有双心室肥厚的WKY-CH大鼠与8只WKY大鼠（左右心室重量正常）进行比较。然后将这些组与9只SHR大鼠进行比较。所有大鼠均在相同条件下饲养。
左心室与体重之比（mg:g）如下：WKY-CH为2.78（标准误0.09）；SHR为2.90（0.09）；WKY为2.10（0.09）。WKY-CH[104（9）]和WKY[111（9）]的收缩压（mmHg）正常，但SHR[163（8）]升高。WKY和WKY-CH的左心室组织学正常，无纤维排列紊乱、纤维化或其他形态学异常。在用泰罗德溶液进行快速容量扩张期间测得的峰值心脏指数（ml·min⁻¹·体重⁻¹），WKY-CH[427（33）]高于WKY[315（33）]和SHR[349（31）]（p<0.05）。当以每毫克左心室重量表示峰值每搏输出量时，各组之间无显著差异。心输出量峰值时的外周阻力（平均动脉压除以心输出量），SHR[1.20（0.12）]高于WKY-CH[0.57（0.08）]或WKY[0.74（0.08）]。
这些数据表明，两种类型的肥厚均增强了左心室峰值功能。在具有正常外周阻力的WKY-CH中，与无左心室肥厚的WKY相比，更大的心室允许更高的峰值心脏指数。在SHR中，较高的左心室质量用于克服增加的外周阻力，从而提供正常的峰值心脏指数。
