Influence of maturation and age on mechanical and biochemical parameters of connective tissue of various organs in the rat.

The mechanical and biochemical parameters of connective tissue components of several organs in rats, e.g. skin, tail tendons and aorta, have been compared. Organ samples have been analyzed at various ages allowing investigation of the changes during maturation and senescence. The age dependent changes in the various organs were quite similar. The parameters indicating strength and elasticity, e.g. ultimate load, ultimate strength, ultimate strain, modulus of elasticity and rate of load increase, rose sharply during the maturation process and decreased during senescence. These values correlated with changes in insoluble collagen but not with those in elastin or glycosaminoglycans as shown in earlier experiments. The relevance of mechanical models to explain age-dependent changes as compared to descriptive correlations between mechanical and biochemical data is discussed.