Reiser P J, Portman M A, Ning X H, Schomisch Moravec C
Department of Oral Biology, Ohio State University, Columbus 43210, Ohio, USA.
Am J Physiol Heart Circ Physiol. 2001 Apr;280(4):H1814-20. doi: 10.1152/ajpheart.2001.280.4.H1814.
The goal of this study was to test the hypothesis that the relative amounts of the cardiac myosin heavy chain (MHC) isoforms MHC-alpha and MHC-beta change during development and transition to heart failure in the human myocardium. The relative amounts of MHC-alpha and MHC-beta in ventricular and atrial samples from fetal (gestational days 47--110) and nonfailing and failing adult hearts were determined. The majority of the fetal right and left ventricular samples contained small relative amounts of MHC-alpha (mean < 5% of total MHC). There was a small significant decrease in the level of MHC-alpha in the ventricles between 7 and 12 wk of gestation. Fetal atria expressed predominantly MHC-alpha (mean > 95%), with MHC-beta being detected in most samples. The majority of adult nonfailing right and left ventricular samples had detectable levels of MHC-alpha ranging from 1 to 10%. Failing right and left ventricles expressed a significantly lower level of MHC-alpha. MHC-alpha comprised approximately 90% of the total MHC in adult nonfailing left atria, whereas the relative amount of MHC-alpha in the left atria of individuals with dilated or ischemic cardiomyopathy was approximately 50%. The differences in MHC isoform composition between fetal and nonfailing adult atria and between fetal and nonfailing adult ventricles were not statistically significant. We concluded that the MHC isoform compositions of fetal human atria are the same as those of nonfailing adult atria and that the ventricular MHC isoform composition is different between adult nonfailing and failing hearts. Furthermore, the marked alteration in atrial MHC isoform composition, associated with cardiomyopathy, does not represent a regression to a pattern that is uniquely characteristic of the fetal stage.
在人类心肌发育及向心力衰竭转变过程中，心肌肌球蛋白重链（MHC）亚型MHC-α和MHC-β的相对含量会发生变化。测定了来自胎儿（妊娠47 - 110天）以及非衰竭和衰竭成年心脏的心室和心房样本中MHC-α和MHC-β的相对含量。大多数胎儿右心室和左心室样本中MHC-α的相对含量较少（平均占总MHC的<5%）。妊娠7至12周期间，心室中MHC-α水平有小幅显著下降。胎儿心房主要表达MHC-α（平均>95%），大多数样本中可检测到MHC-β。大多数成年非衰竭右心室和左心室样本中MHC-α的可检测水平为1%至10%。衰竭的右心室和左心室中MHC-α的表达水平显著降低。在成年非衰竭左心房中，MHC-α约占总MHC的90%，而在扩张型或缺血性心肌病患者的左心房中，MHC-α的相对含量约为50%。胎儿与成年非衰竭心房之间以及胎儿与成年非衰竭心室之间MHC亚型组成的差异无统计学意义。我们得出结论，胎儿人类心房的MHC亚型组成与成年非衰竭心房相同，而成年非衰竭和衰竭心脏的心室MHC亚型组成不同。此外，与心肌病相关的心房MHC亚型组成的显著改变并不代表向胎儿阶段独特特征模式的逆转。
