Studies on the Physiological Ability in relation to Physical Education. : Report 6, Influence of several metabolic substances on the function of perfused toad heart and the movement of isolated rabbit small intestine.

With a view to studying the effect of metabolic substances on the function of the heart, the output of perfused toad hearts, movementcurve, were measured with Yagi-Straub's apparatus, and the amount of oxygen consumption of the ventricular tissue of the heart was also measured. For the sake of comparison, small intestinal movement and the oxygen consumption of incised intestines were measured. The following are the results obtained. 1) The Qo_2 of the ventricular tissue of the heart increased markedly when succinate was added, but other substances showed no remarkable difference. The Qo_2 of the small intestinal tissue decreased when malonic acid was added, but that of ventricular tissue of the heart was not affected by malonic acid. 2) The heart output per minute showed no remarkable change when succinate, pyruvate and creatine were used, but it showed a peculiar increase when lactate was added, and vitamin B_1 also caused it to increase. Lactate exercised a greater influence on the heart output under normal conditions, while vitamin B_1 had a remarkable influence at the time of fatigue. Citrate showed an inhibiting effect. 3) The intestine responded to succinate and malonic acid in the same way as the heart, but it was not inhibited by citrate and accelerated by pyruvate, and was slightly accelerated by lactate