The relation of energy-rich phosphate in muscle to myoglobin and to cytochrome-oxidase activity

Abstract

The relative rates of decrease of aerobic and anerobic energy-rich phosphate during"surviving" metabolism in muscle minces were used as a measure of the muscle''s relative capacities to re-synthesize energy-rich phosphate bonds in the presence of O2. In horse psoas muscle this capacity was found to increase swiftly up to the age of 2 yrs., and thereafter to remain at a relatively steady value. These changes bore a significant direct correlation with corresponding changes in myoglobin concns. and in the activities of the succinic dehydrogenase-cytochrome system. Investigations on various muscles of horse and rabbit showed that high myoglobin concn. (red muscle) was associated with a high capacity for energy-rich phosphate resynthesis aerobically, and high activities of the succinic dehydrogenase-cytochrome system; anaerobically it was associated with a low capacity to effect glycolysis, low adenosine triphosphatase activity and a low energy-rich phosphate store.