OXYGEN TENSION IN RELATION TO ENERGY METABOLISM IN EXERCISING HUMAN SKELETAL MUSCLE

Abstract

This chapter discusses oxygen tension in relation to energy metabolism in exercising human skeletal muscle. Energy metabolism in isolated cells has been shown to be oxygen dependent throughout the whole physiologic range of oxygen tensions. Very little information is available on the dependence of energy metabolism on oxygen in skeletal muscle tissue during exercise. The chapter discusses a study to measure the intramuscular oxygen tension in exercising human skeletal muscle in relation to metabolite levels, which reflect the intracellular energy and redox state. The effect of exercise on these parameters was compared in normal subjects and in patients with peripheral vascular occlusive disease, who have a reduced blood flow during exercise. Ten patients and seven controls were exercised in the supine position using a foot ergonometer at a rate simulating the exercise of walking. The decrease in PO 2 levels was paralleled by changes in metabolite levels. It was found that a decrease in ATP and CrP and an increase in lactate was found at the end of exercise. The more pronounced decrease in PO 2 in patients was also paralleled by a more pronounced change in CrP and lactate.