A FUNCTIONAL DISORDER OF MUSCLE ASSOCIATED WITH THE ABSENCE OF PHOSPHORYLASE

Abstract

Enzymatic analyses were conducted on biopsy specimens of skeletal muscle obtained from a patient characterized by rapid exhaustion of apparently normal muscle which could be prevented by intravenous administration of lactate, glucose or fructose. The muscle contained 4% glycogen and no detectable amounts of phosphorylase a or b. Assayed values of 683 units/g of muscle for phosphorylase kinase and 3870 units/g of muscle for phosphorylase phosphatase indicated that the absence of phosphorylase was specific and not associated with related enzymes. Uridine diphosphate glucose (UDPG)-glycogen transferase was determined and an activity within the normal range of 6 transferase units per gram of tissue was found. The chemical nature of the glycogen formed in the absence of phophorylase had a normal structure. Apparently, glycogen synthesis in the absence of phosphorylase operates via the UDPG mechanism of Leloir and Cardini (J. Am. Chem. Soc. 27: 6340. 1957).