Effects of whole-body X irradiation on the biogenesis of creatine in the rat

Abstract

Influences of whole-body X irradiation on various aspects of creatine metabolism have been studied. Exposures to sublethal or lethal doses of X radiation results in excessive urinary excretion as well as higher accumulation of creatine in the skeletal muscle of X-irradiated rats. A sudden fall in CPK activity in muscle with a concomitant rise in serum suggests that changes in serum and tissue CPK activity are of an adaptive nature in rats exposed to sublethal doses of X radiation. In vitro studies on creatine synthesis shows that transaminidase and methyl transferase activities in kidneys and liver, respectively, are decreased on the 5th day in the X-irradiated rat. However, on the 8th day, the enzyme activities are restored to normal.