Effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride on heart function, lactate dehydrogenase and its isoenzymes in rats with cardiac hypertrophy.

AIM

To investigate the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on cardiac systolic and diastolic function, lactate dehydrogenase (LDH) activity, and LDH isoenzymes in rats with cardiac hypertrophy.

METHODS

The cardiac hypertrophy of rats was induced by partly occluding abdominal aorta. The rats were given i.g. DDPH for 8 wk 4 wk after operation, and isolated working heart was made.

RESULTS

Eight wk later, in model group, left ventricle systolic pressure (LVSP), LV + dp/dtmax, -dp/dtmax and aorta pressure (AP) decreased by 20.2%, 20.0%, 41.4%, and 13.6%, respectively. Left ventricle ending diastolic pressure (LVEDP) increased by 173.9%. The hemodynamic study showed that flowing liquid of aorta (AF) and coronary (CF) and cardiac output (CO) decreased by 49.4%, 41.2%, and 48.9%, respectively. After the rats were given i.g. DDPH, the all above-mentioned parameters recovered to different degrees. Under condition of cardiac hypertrophy, LDH isoenzymes and subunits changed significantly. Isoenzymes LDH3, LDH4, and LDH5, especially LDH5 increased, LDH1 decreased, subunit M in hypertrophied heart increased 1.69 times than that in normal heart. DDPH could decrease subunit M and increase subunit H.

CONCLUSION

DDPH can increase cardiac function, coronary flow and reverse changes of LDH isoenzymes in rats with cardiac hypertrophy.