COMPARATIVE METABOLISM OF H-3 GLUCOSAMINE BY FIBROBLAST POPULATIONS EXPOSED TO CYCLOSPORINE

CYCLOSPORINE AND NIFEDIPINE THERAPY produces gingival overgrowth in ma ny patients. Neither the mechanism underlying this undesirable side ef fect nor the possibility of synergism between these drugs is known, al though many renal transplant patients receive both drugs. This study c ompared the rates of H-3-glucosamine utilization by three groups of fi broblasts: untreated gingival fibroblasts, fibroblasts from gingival o vergrowth tissue of a patient receiving both cyclosporine and nifedipi ne, and normal gingival fibroblasts exposed to cyclosporine-A in vitro . Significant differences in the rates of deposition of H-3-glucosamin e into the extracellular matrix by each group of gingival fibroblasts were demonstrated, suggesting that increased rates of deposition of pr oteoglycans into the gingival extracellular matrix by fibroblasts shou ld be further investigated as a biologic mechanism for gingival overgr owth.