THE MODE OF EXCRETION OF CREATINE AND CREATINE METABOLISM IN THYROID DISEASE 1

Abstract

In normal adults and in [male] and [female] patients with thyroid disease, creatine appeared in the urine only when its conc. in the serum was 0.58 mg.% or more. In [male][male] it did not exceed this limit, the serum creatine rose little after adm. of 1 g. creatine and creatinuria was minimal. In [female][female], even if postabsorptive serum creatine was low and creatinuria lacking, adm. of creatine induced a greater rise of serum creatine and more creatinuria than in [male][male]. In hyperthyroidism, postabsorptive serum creatine was usually high and attended by creatinuria; alimentary creatinemia and creatinuria were exaggerated. Iodine therapy tended to restore these reactions to normal. Creatine was completely reabsorbed by the renal tubules when its conc. in the serum was less than 0.5 mg.%. Above this the clearance of creatine rose as its conc. in the serum increased. The creatine clearance remained always lower than the creatinine clearance. Therefore no evidence of creatine secret ion was obtained.