Excretion of Glycosaminoglycans and Glycoproteins in Normal Human Urine with Age

Abstract

The non-dialyzable fractions of glycosaminoglycans and glycoproteins obtained from the urine of one hundred healthy Japanese were determined by gravimetric analysis after fractionation with CPC (cetylpyridinium chloride). 1) Although there was a marked variation in the concentration of these fractions, children showed relatively higher values than adults. 2) The amounts of these fractions in 24-hr urine increased with age in children, but remained constant after puberty. 3) The relative amounts of these fractions, expressed as mg/24-hr urine/kg body weight, increased with age in younger children, and then decreased to an almost constant level in adults. 4) Although the daily excretion of these fractions showed a tendency to be larger in males than in females, no significant difference could be found in the relative amounts between them. 5) The ratios of the glycoprotein fraction to the glycosaminoglycan fraction increased with age in younger children, but remained almost constant after puberty. 6) These observations indicated higher metabolic rate of these substances in children than in adults. Moreover, the data of the group 3 (10_??_14 years of age) showed that it might represent the period of transition between child and adult. 7) Certain correlations were found between the relative amounts of the glycoprotein fractions and those of the glycosaminoglycan fractions in the subjects either below or over 15 years of age. The equation of regression suggested that there might be two groups of glycoproteins in urine. One group was thought to contain the metabolites of the ground substance of the connective tissues, whereas the other seemed to consist of serum glycoproteins and/or glycoproteins of somatic fluids without relation to the connective tissues.