Vulpis V, Ricci S, Seccia T M, Lograno M, Daniele E, Pirrelli A
Sezione di Medicina Interna, Università degli Studi, Bari.
Cardiologia. 1996 Sep;41(9):877-82.
Changes of the contractile proteins in the left ventricle from spontaneously hypertensive rats (SHR) are extensively documented with the development of the hypertensive state and with ageing. This study was undertaken to determine whether also the left ventricle from normotensive rats exhibits age-related changes of the myosin pattern. The relative distribution of myosin isoforms was investigated in Wistar Kyoto (WKY, n = 50) and SHR (n = 50), both at the 5th, 9th, 24th, 48th and the 72nd week of life. A significant decrease in V1 as well as an increase in V3 percentage values, compared to the data obtained at the 5th week were observed in SHR from the 9th week, concomitantly to the rise in blood pressure values. These changes were more consistent with ageing (5 weeks: V1 99.0 +/- 0.9%, V2 0.6 +/- 0.1%, V3 0.4 +/- 0.3%; 72 weeks: V1 5.3 +/- 3.9%, V2 3.0 +/- 2.7%, V3 91.7 +/- 9.7%). In WKY rats, a significant decrease in V1 percentage values was detected at the 24th week and it was evident till the 72nd week. V3 significantly changed only at the 48th and the 72nd week (5 weeks: V1 100.0 +/- 0.0%; 72 weeks: V1: 41.4 +/- 6.5%, V2 13.3 +/- 2.8%, V3 45.5 +/- 6.9%). The results of this study confirm that alterations in the left ventricle isomyosin pattern occur early in SHR with the rise in blood pressure values and the increase in left ventricular mass. In contrast, modifications in the myosin isoform distribution were found only in WKY with ageing. These findings may be related to the biochemical changes occurring in the myocardial tissue either gradually, during the advanced ages of life, or early due to the hypertensive state.
随着高血压状态的发展以及衰老，自发性高血压大鼠（SHR）左心室收缩蛋白的变化已有大量文献记载。本研究旨在确定正常血压大鼠的左心室是否也表现出与年龄相关的肌球蛋白模式变化。研究了Wistar Kyoto大鼠（WKY，n = 50）和SHR（n = 50）在生命的第5、9、24、48和72周时肌球蛋白同工型的相对分布。与第5周获得的数据相比，从第9周起，SHR中V1显著降低，V3百分比值增加，同时血压值升高。这些变化与衰老更为一致（5周：V1 99.0 +/- 0.9%，V2 0.6 +/- 0.1%，V3 0.4 +/- 0.3%；72周：V1 5.3 +/- 3.9%，V2 3.0 +/- 2.7%，V3 91.7 +/- 9.7%）。在WKY大鼠中，第24周时检测到V1百分比值显著降低，直到第72周仍很明显。V3仅在第48周和第72周有显著变化（5周：V1 100.0 +/- 0.0%；72周：V1：41.4 +/- 6.5%，V2 13.3 +/- 2.8%，V3 45.5 +/- 6.9%）。本研究结果证实，SHR左心室异肌球蛋白模式的改变随着血压值升高和左心室质量增加而在早期出现。相比之下，仅在衰老的WKY大鼠中发现肌球蛋白同工型分布的改变。这些发现可能与心肌组织中逐渐发生的生化变化有关，这些变化要么在生命晚期逐渐发生，要么由于高血压状态在早期发生。
