Age-related changes of plasma glycosaminoglycans.

BACKGROUND: This study was undertaken to reveal how the physiological ageing process influences plasma glycosaminoglycans (GAGs) content and composition.
METHODS: GAGs isolated from plasma samples obtained from 105 healthy subjects were quantified using a hexuronic acid assay and subjected to electrophoretic fractionation.
RESULTS: We found that total GAGs decreased gradually with advancing age. The electrophoretic analysis allowed identifying chondroitin sulfates, dermatan sulfates and heparan sulfates and heparin in plasma of healthy individuals. Chondroitin sulfates, predominant plasma GAGs, showed declining values with age and displayed higher structural diversity in subjects from the first five decades of life compared to older subjects. An age-related increase in plasma dermatan sulfates content during the first four decades of life followed by a decrease in a later period of life was apparent. Structural heterogeneity of these glycans was found in subjects until 10 years of age. Heparan sulfates and heparin plasma levels were inversely correlated with age until 25 years of age, without age-dependent changes thereafter. These macromolecules displayed higher heterogeneity of structure in subjects over 50 years of age than in younger subjects.
CONCLUSIONS: The obtained results indicate that age should be taken into account in all studies investigating blood GAGs alterations during pathological conditions.