Conrad C H, Brooks W W, Robinson K G, Bing O H
Department of Medicine, Boston Veterans Affairs Medical Center, Massachusetts 02130.
Am J Physiol. 1991 Jan;260(1 Pt 2):H136-45. doi: 10.1152/ajpheart.1991.260.1.H136.
We have observed that many spontaneously hypertensive rats (SHR) between the ages of 18 and 24 mo develop findings suggestive of heart failure, including pleural and pericardial effusions, left atrial thrombi, and right ventricular hypertrophy. Isolated left ventricular papillary muscle function was studied in these animals (SHR-F), in age-matched SHRs without evidence of heart failure (SHR-NF), and in nonhypertensive controls (WKY). Preparations from SHR-F showed depression of active tension development (3.58 +/- 1.75 g/mm2, means +/- SD) compared with both SHR-NF (7.17 +/- 0.94) and WKY (6.17 +/- 1.00) (P less than 0.01). Shortening velocity was also depressed in SHR-F (0.95 +/- 0.38 lengths/s) compared with SHR-NF (1.60 +/- 0.30; P less than 0.05) and WKY groups (2.15 %/- 0.48; P less than 0.01). Depression of muscle function was not found before 18 mo of age. Thus the aging SHR is a model in which one can observe the transition from chronic stable left ventricular hypertrophy to overt heart failure. Furthermore, left ventricular papillary muscles from SHRs with heart failure show evidence of significant contractile dysfunction, suggesting that impairment of intrinsic myocardial function underlies the development of heart failure.
我们观察到，许多18至24月龄的自发性高血压大鼠（SHR）出现了提示心力衰竭的表现，包括胸腔和心包积液、左心房血栓以及右心室肥大。对这些动物（SHR-F）、无心力衰竭证据的年龄匹配SHR（SHR-NF）以及非高血压对照（WKY）的离体左心室乳头肌功能进行了研究。与SHR-NF（7.17±0.94）和WKY（6.17±1.00）相比，SHR-F的标本显示主动张力发展降低（3.58±1.75 g/mm2，平均值±标准差）（P<0.01）。与SHR-NF（1.60±0.30；P<0.05）和WKY组（2.15±0.48；P<0.01）相比，SHR-F的缩短速度也降低（0.95±0.38长度/秒）。在18月龄之前未发现肌肉功能降低。因此，老龄SHR是一种可以观察从慢性稳定左心室肥大到明显心力衰竭转变的模型。此外，患有心力衰竭的SHR的左心室乳头肌显示出明显的收缩功能障碍，这表明心肌内在功能受损是心力衰竭发展的基础。
