Age related changes in the synthesis of connective tissues in the rabbit

The synthesis of collagen and non-collagen proteins was studied in rapidly growing male New Zealand rabbits. Animals were divided into sexually immature (i.e. 4 and 8 week old) and mature (i.e. 15 and 26 week old) groups. Comparisons of aorta, lung, and liver protein synthesis and accumulation were made to determine the effect of aging on both collagen and non-collagen proteins. In all tissues there appeared to be an age-related decrease in the relative percent of collagen synthesized. In the lung and liver the relative decrease in percent collagen synthesis resulted from an age-related increase in the synthesis rate of non-collagen proteins. In the aorta the decrease in percent collagen synthesis was primarily a result of a dete of accumulation of tissue proteins correlates more directly with the growth and degree of differentiation of a tissue than with direct animal age.