URIDINE-DIPHOSPHATE HEXOSES IN LEUKOCYTES AND FIBROBLASTS OF CLASSIC GALACTOSEMICS AND PATIENTS WITH OTHER METABOLIC DISEASES

To examine uridine diphosphate hexose (UDPhexose) content of cells tha t have more complete metabolic patterns than erythrocytes, which have been commonly used in the study of galactosemia, the concentrations of uridine diphosphate galactose (UDPgalactose) and uridine diphosphate glucose (UDPglucose) were determined in white blood cells (WBC) and fi broblasts cultured from skin biopsies. Leukocyte UDPgalactose and UDPg lucose values were determined in 60 normal individuals, 14 classic gal actosemics, and 18 patients with other metabolic diseases on protein-r estricted and low-lactose diets. There was no difference in the averag e concentration of these compounds between any of these groups. There was no relationship between age and WBC UDPhexose content or correlati on of WBC and erythrocyte UDPhexose levels in the same blood specimens . WBC from galactosemic individuals differ from their red blood cells because the former do not show the low average UDPgalactose levels and abnormal UDPglucose to UDPgalactose ratio previously reported for ery throcytes from galactose-1-phosphate uridyltransferase-deficient indiv iduals. Fibroblast cell lines from 10 normal and 10 galactosemic indiv iduals, cultured and grown to confluence in glucose medium, also showe d no difference in nucleotide sugar concentrations. Thus far, of the c ell types easily available, red blood cells appear to be unique in sho wing an abnormality in nucleotide sugar metabolism. The fact that gala ctosemic fibroblasts demonstrate no abnormality in the concentration o f these compounds suggests that the defective galactosylation that has been observed in galactosemic fibroblasts is not due to unavailabilit y of UDPgalactose.