The excretion of the two hydroxylysine glycosides hydroxylysine-galactose-glucose and hydroxylysine-galactose was studied in the urine of normal healthy and experimental rats chronically treated with collagen-like syndrome inductors, hydralazine or binazine. The elevated urinary hydroxylysine-galactose-glucose and hydroxylysine-galactose strongly suggests an altered rate of collagen degradation during induced collagen-like syndrome.