COMPARATIVE EFFECTS OF CYCLOSPORINE ON GLYCOSAMINOGLYCAN SYNTHESIS BYGINGIVAL FIBROBLASTS

HISTOLOGICAL STUDIES SHOW THAT drug-induced gingival overgrowth result s from an accumulation of the connective tissue component. Despite com prising a major part of gingival connective tissue, a role for glycosa minoglycans (GAGs) in the pathogenesis of gingival overgrowth has rece ived scant attention. By analysing the metabolism of H-3-glucosamine, we have compared GAG and hyaluronan synthesis by fibroblasts derived f rom normal and overgrown gingival tissue, and the effects of cyclospor in on GAG output. GAG production was cell density-dependent, fibroblas ts cultured at low density synthesizing significantly increased quanti ties in comparison to confluent cultures. The effects of cyclosporin o n GAG synthesis was also found to be both cell density- and cell strai n-dependent, However, cyclosporin-stimulated GAG synthesis by 2/3 over grown cell strains and 1/3 normal strains. These results suggest that a direct promotion of GAG synthesis by gingival fibroblasts in respons e to cyclosporin may play a role in the pathogenesis of gingival overg rowth.