Connective Tissue VII. Changes in Protein and Hexosamine Content of Bone and Cartilage of Rats at Different Ages. ∗

Summary

1. Proteins of bone and cartilage from skull, femur, rib and vertebrae of female rats, Wistar strain, age 5 weeks and 2 1/2 years, respectively, were fractionated into TCA supernatant of base soluble protein, nonscleroprotein, soluble collagen, insoluble collagen, glycoprotein and elastin. 2. With an increase in age, there was a decrease of protein and hexosamine in TCA supernatant of base soluble protein, nonscleroprotein and soluble collagen of both bone and cartilage. 3. The amount of insoluble collagen in skull, femur and rib did not change with age; in vertebrae it increased and in cartilage, it decreased. 4. Certain glycoproteins, not present in the connective tissues studied, other than bone and cartilage, decreased in bone and increased in costal cartilage wtih increasing age.