Collagens of oral soft tissues. I. The influence of age on the synthesis and maturation of collagen in rat palatal mucosa as determined in vitro.

The rate of collagen synthesis in rat palatal mucosa decreased markedly from 2.5 to 13 weeks of age when determined by an in vitro labelling technique. Beyond 13 weeks of age, the rate of collagen synthesis remained unchanged and at a relatively low level. These results were not a consequence of isotope-dilution arising from an increase of tissue collagen mass. For other connective tissues an age-dependent decrease in net collagen synthesis has been observed and, therefore, is not unique for palatal mucosa. The principal finding of this study was that the rate of conversion of salt-soluble to salt-insoluble collagen in palatal mucosa increased with age and remained at a high level in adult rats. In contrast, the rate of conversion of salt-soluble to -insoluble collagen has been reported to decline in adult rat skin. Collectively, the data suggest that collagen in soft oral connective tissues undergoes fibrillogenesis with a rapidity that may be more characteristic of tissues during rapid growth or during healing, rather than tissues during a normal adult stage of metabolism.