CARBOHYDRATE CHANGES DURING RECOVERY FROM MUSCULAR CONTRACTION

Abstract

Expts. on rabbits showed that the entire amt. of lactic acid formed during anaerobic activity in muscle diffuses into the blood stream during recovery. Glycogen is not formed in the muscle during recovery from any of the lactic acid produced in anaerobic activity. The "''Meyer-hof cycle" is shown to be of no significance in recovering mammalian muscle. Hexosephosphate, which is formed during contraction, is resynthesized directly to glycogen during recovery, without intermediate breakdown to lactic acid. The rate at which hexosephosphate is re-synthesized to glycogen is practically constant throughout the recovery period. Additional evidence is presented that the sole function of phosphocreatine hydrolysis in muscle is the maintenance of constant pH within the fiber. The data confirm the theory that the reactions which yield energy for muscular activity are primarily oxidative.