The fate of ingested creatinine in the rat

Abstract

Creatinine administered orally to normal and to cecectomized adult rats in doses of 30 to 60 mg./rat was excreted in the urine in amts. up to 85% of the dose. No increased creatinuria was induced. Creatinine also appeared in the feces, the fraction of the dose excreted in this manner together with the fraction eliminated in the urine accounting completely, within the limits of exptl. error, for the administered dose. Oral creatinine is only partly absorbed from the intestine, the portion of the dose which is absorbed being immediately and completely excreted. It is considered unnecessary to postulate any metabolism or retention of oral creatinine. In expts. in vivo and in vitro, creatinine was found to suffer little or no bacterial destruction in the intestine.