A re-appraisal of the function and synthesis of phosphoarginine and phosphocreatine in muscle

Natural Guanidino Compounds

“…This regulation apparently can be under the direct control of the phosphagen concentration in muscle (Storey, 1976). Alternatively, the acceptance of phosphate by arginine in invertebrate muscle and by creatine in vertebrate muscle following exercise, permits the resting muscle to remote inorganic phosphate to rate-limiting levels in order to control glycogenolysis and glycolysis (Davuluri et al, 1981) .…”

Effects of ischemia on skeletal muscle energy metabolism in mice lacking creatine kinase monitored byin vivo31P nuclear magnetic resonance spectroscopy

“…P i levels regulate glycogenolysis and/or glycolysis since these pathways require P i for their activation. 3 Although the PCr-CK system has been studied in much detail, there is little direct evidence for the significance of these different functions in whole animals. Functional studies mostly involved feeding of creatine analogs as a tool to modify the system directly.…”