The effect of oxygen on Cor pulmonale in experimental emphysema induced by elastase or elastase and beta-aminopropionitrile in hamsters.

Right ventricular hypertrophy in elastase-induced emphysema in the System hamster was assessed by either the weight of the right ventricle as a fraction of body-weight or by the ratio of the weight of the right to the left ventricle. Right ventricular hypertrophy accompanies elastase-induced emphysema and is more severe in hamsters injected with elastase while fed a diet containing 0.5% beta-aminopropionitrile (BAPN), a combination that causes more severe emphysema. Measurements of arterial blood oxygen pressures showed that emphysematous animals were hypoxemic. Treatment of emphysematous animals with 35% O2 either during the development of right ventricular hypertrophy or after it had developed produced measurable amelioration of the hypertrophy in those groups with the more severe emphysema (elastase plus BAPN diet) but did not completely prevent it. The oxygen had no effect on the severity of the emphysema measured morphometrically. These results indicate that the cor pulmonale in elastase-induced emphysema is probably multifactorial, but hypoxia appears to be one of the major factors.