Peculiarities of Collagen Turnover in Aging BALB/c Mice

Examination of collagen turnover in the liver, lungs, and spleen of BALB/c mice revealed the age-related differences in the levels of hydroxyproline and its fractions. The highest level of total hydroxyproline was observed in the lungs and spleen of young (2-month-old) mice. In the liver, this level attained maximum at the age of 6 months at the expense of elevation of protein-bound hydroxyproline relatively its level in 2-month-old mice. At the age of 12 months, the levels of total hydroxyproline in the liver and spleen were lower than in 6-month-old mice. The decrease in the collagen turnover rate in the liver of 12-month-old mice reflected lower levels of hydroxyproline fractions in comparison with the corresponding values in 6-month-old mice. The rates of collagen turnover in organs differed in mice of different ages: it was maximum in the lungs and spleen of young animals and in the liver of middle-aged mice.