Increased urinary excretion of acid mucopolysaccharides and glycopeptides in hypothyroidism following thyroid hormone therapy.

Urinary excretion of acid mucopolysaccharides and glycopeptides in the urine of an untreated patient with cretinism were measured before and after thyroid hormone replacement. Urinary uronic acid and hexose excretion in the CPC-precipitated fraction increased four to ten times after thyroid hormone administration. The maximum excretion was observed after 2 months of thyroid replacement. The excreted acid mucopolysaccharides consisted of chondroitin sulphate A/C and minor quantities of heparan sulphate. Urinary excretion of glycopeptides, particularly small molecular glycopeptides rose also four to five-fold with thyroid hormone administration. These data suggest that thyroid hormone markedly influences the metabolism of acid mucopolysaccharides and glycoproteins. Possibly, the lack of thyroid hormone caused a decreased activity of various lysosomal glycosidases and sulphatases.