与衰老和慢性高血压相关的心肌肌球蛋白同工酶改变：硝苯地平对其的调节作用。

Raizada V, Pathak D, Blomquist T M, Minser R, Woodfin B

Department of Medicine, University of New Mexico, Albuquerque 87131.

Cardiovasc Res. 1993 Oct;27(10):1869-72. doi: 10.1093/cvr/27.10.1869.

OBJECTIVE

Pressure induced left ventricular hypertrophy is associated with alterations in distribution of cardiac myosin isozymes. This study evaluated the influence of aging, superimposed chronic hypertension on aging, and treatment with nifedipine on cardiac myosin isozyme proportions.

METHODS

Myosin isozyme (V1, V2, and V3) proportions were investigated by pyrophosphate gel electrophoresis, and left ventricular to body weight ratio was studied in two subgroups each of hypertensive and normotensive rats, with and without nifedipine treatment. Nifedipine treatment was started at 48 weeks and concluded at 60 weeks.

RESULTS

For all four groups, the V1 level was the lowest (range 15%-24%), V3 was the highest (47%-60%), and V2 was intermediate (25%-29%). The left ventricular weight to body weight ratio was 25% higher (p < 0.001) in the untreated old hypertensive v old rats, but V1 level was of the same magnitude in both these groups. The left ventricular weight to body weight ratio was 18% lower (p < 0.001) in the old hypertensive treated v untreated rats. The V1 level was higher in both treated groups; old normotensive as well as old hypertensive rats. The changes in V1 were not statistically correlated with arterial pressure and left ventricular to body weight ratio.

CONCLUSIONS

The profound decrease in V1 myosin isozyme proportion acquired with aging is not accentuated by superimposed chronic hypertension. The aging process, and not the left ventricular hypertrophy by itself, seems to be the principal determinant of the myosin isozyme shift. The myosin isozyme shift that occurs with aging is not fixed, and can be partially reversed or prevented by nifedipine.

目的

压力诱导的左心室肥厚与心肌肌球蛋白同工酶分布的改变有关。本研究评估了衰老、叠加的慢性高血压对衰老的影响以及硝苯地平治疗对心肌肌球蛋白同工酶比例的影响。

方法

采用焦磷酸凝胶电泳研究肌球蛋白同工酶（V1、V2和V3）比例，并在有或无硝苯地平治疗的高血压和正常血压大鼠的两个亚组中研究左心室与体重比。硝苯地平治疗于48周开始，60周结束。

结果

对于所有四组，V1水平最低（范围为15%-24%），V3最高（47%-60%），V2居中（25%-29%）。未治疗的老年高血压大鼠与老年大鼠相比，左心室重量与体重比高25%（p<0.001），但这两组的V1水平相当。老年高血压治疗组与未治疗组相比，左心室重量与体重比低18%（p<0.001）。在两个治疗组中，即老年正常血压大鼠和老年高血压大鼠中，V1水平均较高。V1的变化与动脉压和左心室与体重比无统计学相关性。