THE CHANGES OF MYOSIN ATPase ACTIVITY AND ITS ISOENZYME DISTRIBUTION IN EARLY STAGE OF CARDIAC HYPERTROPHY FOLLOWING MYOCARDIAL INFARCTION IN RATS / 西安交通大学学报(医学版)

ABSTRACT

To investigate the changes of cardiac myosin ATPase and its isoenzyme in early stage of cardiac hypertrophy following myocardial infarction(MI), we studied myosin ATPase activitzy, isoenyme distriibution and myocardial fiber diameter of uninfarcted ventricu lar sfptum, 9 aed 21 days after operation in MI rats. The results showed that coincident with the increases in myocardial fiber diameter on 9 days after MI, both myosin ATPase activity and V_1 isoenzyme amount were depressed. These changes were more pronounced on 21 after MI. It is suggested that with the development of myocardial hypertrophy in early stage of MI, adaptive changes in myosin ATPase activity and isoenzyme distribution occur.