IN-VITRO BIOSYNTHESIS OF TYPE-I AND TYPE-III COLLAGENS BY HUMAN DERMAL FIBROBLASTS FROM DONORS OF INCREASING AGE

A quantitative study of type I and type III collagen production was ca rried out on primary cultures of human dermal fibroblasts. Cultures we re initiated from facial and mammary skin of 29 women aged between 19 and 68 years. Secreted and cell-associated collagen levels were determ ined by an enzyme linked immunosorbent assay (ELISA). We found that th e secretion of type I and type III collagen decreased linearly with ag e (r = 0.432; P = 0.0193 and r = 0.502; P = 0.0147, respectively). The re was a 29% loss in secretion ability for type I and type III collage n over the 49-year period studied. Furthermore, no significant linear age-related decrease was observed for type I and type III collagen ass ociated with the cellular fraction. The influence of body site was als o analysed. We observed a significant linear age-related decrease in t ype I collagen secretion by mammary skin cells (P = 0.0183 and r = 0.6 18) as well as facial skin cells (P = 0.0037 and r = 0.699). Furthermo re, only mammary skin fibroblasts showed a significant linear age-rela ted decrease in secreted type III collagen (P = 0.106 and r = 0.513). No age-related variations in cell-associated collagen were found.