Age-Related Variations in Proteinpolysaccharides from Human Nucleus Pulposus, Annulus Fibrosus, and Costal Cartilage

Light fraction proteinpolysaccharide was prepared by water extraction of nucleus pulposus, annulus fibrosus, and costal cartilage obtained at autopsy from fifteen skeletally normal subjects ranging in age from four and one half to seventy-six years. Age dependent changes in glucosamine and galactosamine content of the crude tissue and of the light fraction proteinpolysaccharide were demonstrated. A decrease with aging in per cent of total hexosamine extractable in the light fraction proteinpolysaccharide and an increase in protein content was observed in all three tissues. Electrophoresis of the light fraction produced two main components differing in both polysaccharide and protein content.