CREATINURIA OF INFANCY AND CHILDHOOD: I. NORMAL VARIATIONS: CREATINE TOLERANCE TESTS AND THE EFFECT OF AMINO-ACETIC ACID IN NORMAL INFANTS

The metabolism of creatine and creatinine has attracted widespread interest in recent years. Although creatinine was first recognized in 1832,1 the impetus to study its metabolism arose from the publication by Folin2 in 1904 of a simple method for its determination. Numerous investigations during the last three decades have established the constancy of the presence of creatinine in the urine and of creatine under certain normal and pathologic conditions. The regularity of the excretion of creatinine indicated that it was a waste product of the body, but the function of creatine remained an open question, although the Eggletons3 and Fiske and Subbarow4 have recently demonstrated the importance of phosphocreatine in muscle metabolism.The classic monograph by Hunter5 summarized the results of studies of creatine and creatinine up to 1928. This was supplemented by the review of Rose6 in 1933. No attempt, therefore, will be