A new microfluorometric method for the measurement of galactose-1-phosphate in erythrocytes.
A new and sensitive assay for measuring galactose-1-phosphate in erythrocytes is described. Galactose-1-phosphate is determined by mixing an aliquot of deproteinized hemolysate with a reagent containing uridine diphosphoglucose, NADP+, hexose-1-phosphate uridylyltransferase, phosphoglucomutase, glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase and measuring the NADPH formed fluorometrically. Under the conditions of this assay 2 mol of NADPH are formed per mol of galactose-1-phosphate. The assay is linear from 0 to 1160 micrograms of galactose-1-phosphate per gram of hemoglobin. Recovery of galactose-1-phosphate added to four hemolysates averaged 99%. Galactose-1-phosphate concentrations were measured in erythrocytes from five heterozygous subjects not under dietary control and seven transferase-deficient galactosemic individuals who were receiving galactose restricted diets. In all samples from the heterozygous individuals, the galactose-1-phosphate concentrations were normal. Of the samples from galactosemic subjects, two showed extreme elevations of galactose-1-phosphate, four showed moderate elevations, and one was normal. Galactose-1-phosphate levels are used to monitor the degree of dietary control in the transferase-deficient galactosemic individual.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000032:analysis*; D005260:Female; D005470:Fluorometry / Q000379:methods; D005693:Galactosemias / Q000097:blood; D005695:Galactosephosphates / Q000097:blood*; D006600:Hexosephosphates / Q000097:blood*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008832:Microchemistry / Q000379:methods; D012016:Reference Values
D005695:Galactosephosphates; D006600:Hexosephosphates; C029973:galactose-1-phosphate