SELECTIVE-INHIBITION OF COLLAGEN-SYNTHESIS BY FLUORIDE IN HUMAN PULP FIBROBLASTS INVITRO

Human dental pulp cells were cultured in fluoridated mediums (0, 1, 10 , 25 ppm) in order to study the biological effect of the ion regarding the cellular metabolism: cell growth, alkaline phosphatase (ALP) acti vity, and protein synthesis. The results indicated a decrease of the c ell growth at 25 ppm and a dose-dependent decrease of the ALP activity . Type I collagen immunoperoxidase staining, radioimmunoassay quantita tion, and analysis of type I and III collagens mRNA levels showed an i nhibition of collagen production and gene expression. In contrast, fib ronectin production and gene expression were not affected by fluoride. The treatment did not influence the qualitative pattern of the differ ent mRNA species. Of the three collagen chains, the alpha1(I) was the most affected. These data suggest that fluoride does not exert a gener al depletive effect on human dental pulp cells but rather a selective inhibition on collagen production.