Oxygen Consumption of the Auricles, Right and Left Ventricles of the Normal, Hypothyroid and Hyperthyroid Rat Heart

¹ From the Department of Biochemistry, University of Louisville School of Medicine, Louisville, Kentucky

A study of the oxygen consumption of the atrium, right and left ventricles from rat heart has been reported. The response of these heart regions to the in vitro and in vivo addition of thyroxine has been reported. Results obtained were: a) The oxygen consumption of the left ventricle from normal animals was found to be about 25% greater than that of the right ventricle and atrium. b) In animals whose thyroid activity was depressed the oxygen consumption of the atrium and the right and left ventricles was proportionately decreased about 25%. c) Animals whose thyroid activity was increased were found to have an increased oxygen consumption in all areas of the heart, however, not proportionately. d) The in vitro addition of thyroxine to the three heart areas from animals with decreased thyroid activity and normal animals caused an increase in oxygen consumption, whereas it did not appreciably affect the oxygen consumption of the heart areas from animals with increased thyroid activity.