Disturbance of Creatine Metabolism in Rats with Chronic Renal Failure

Abnormalities in creatine metabolism have been reported in chronic renal failure (CRF)1–2. In chronic uremic patients, levels of guanidinoacetic acid (GAA) and creatine in plasma are decreased. The mechanism of this phenomenon is not entirely understood. The present report describes a study of creatine metabolism in rats with CRF. Creatine and GAA levels in plasma, kidney and liver were measured. Glycine amidinotransferase (GAT) activity in the kidney and guanidinoacetic acid methyltransferase (GAA-MT) activity in the liver were determined. A radioisotopic evaluation of the metabolites of the creatine pathway using 14C-glycine and 14C-GAA was also carried out.