In Vitro Augmentation of Muscle Oxygen Consumption by Hemoglobin

Abstract

Summary

Frog skeletal muscle Qo₂ increased hyperbolically with increasing Po₂ when the latter was varied from 19 to 154 mm Hg. Shaking the reaction vessels at 60 cpm or adding 1% hemoglobin to the media significantly increased muscle respiration. However, while shaking alone increased both the rate of rise of Qo₂ with increasing Po₂, as well as the calculated maximum Qo₂ at infinite oxygen supply, addition of hemoglobin significantly increased only the rate of Qo₂ rise (maximal effect at Po₂ = 72.5 mm Hg) but not maximum Qo₂. When the two treatments were tested together, shaking potentiated the hemoglobin effect. A variety of related substances tested did not augment muscle respiration. The results suggest that hemoglobin increases the availability of oxygen to tissues by increasing the rate of diffusion of oxygen from media to cells in a manner related to the facilitated diffusion observed in hemoglobin films.