Effects Of Chronic Hypoxia On Ventricular Functions, Structures And Contractile Proteins-Comparison Between Right And Left Ventricles

The effect of hypoxia on cardiac functions is an important topic in medical field. During the development of pulmonary hypertension caused by chronic hypoxia, the compensatory mechanisms and compensatory abilities of right and left ventricles are of great significance. However,a systematic and comparative study on this topic has not been reported yet.In this study, the hemodynamic and the histologic changes at organic and cellular levels, and changes in ventricular myofibrillar ATPase activities and myosin isoenzyme distributions were examined. Differences between right and left ventricles were compared .The results are as follows. The animal survival rate of simulated 5000m above sea level hypoxia for 4,10 and 20 days were all 100%, 81 % for 40 days hypoxia at this level, and 42% for 4 days hypoxia at 8000m, 25% for 10 days hypoxia at 8000m. In moderate hypoxia at 5000m, right ventricular function increased significantly because of high pulm(?)aary pressure but increase in left ventricular function was not significa(?)t in 5000m hypoxia. However, in 8000m hypoxia right ventricular fu(?)tion rather decreased more or less, but left ventricular function dec(?)ased significantly, especially in \ days hypoxia at 8000m. This may be due(?) the fact that left ventricle has a greater pumping function and higher o(?)gen consumption than that of right ventricle; thus, the direct damage by (?)rupt and severe deficiency of oxygen supply to left ventricle is more sever(?) than that to right ventricle. In moderate hypoxia deficiency of oxygen sup(?)y is not severe and the body can bring its compensatory mechanisms at dif(?)rent...