Comparative metabolism of 3H-glucosamine by fibroblast populations exposed to cyclosporine
The aim of this study was to compare the rates of 3H-glucosamine utilization by three groups of fibroblasts: untreated gingival fibroblasts (F), fibroblasts from gingival overgrowth tissue (OG) from a patient receiving both cyclosporine and nifedipine, and normal fibroblasts exposed to cyclosporine in vitro (CF). Human gingival fibroblast cultures were established from gingival biopsies from healthy donors and patient A (a diabetic Canadian male).Three comparative rates of uptake of 3H-glucosamine into glycosaminoglycans by the three groups were measured on cells in the sixth passage. Mean counts (silver grains) were compared by one- or two-way analysis of variance and a post-hoc Tokey's test. Regression lines were fitted to data and slopes. Slopes were compared to analysis of covariance. Ten minutes after introduction of 3H-glucosamine showed that the number of silver grains over OG and F declined, but it remained higher over OG than over F. Silver grains over CF progressively increased during this period. The rate of incorporation of silver grains into adjacent matrix was greatest in CF population and was greater in OG cells than in F populations. In conclusion, increased tissue levels of non-sulfated glycosaminoglycans could occur coincident to cyclosporine A exposure. Increased glycosaminoglycan levels should not be dismissed as a biologic mechanism for gingival overgrowth coincident to cyclosporine-A treatment. [c.c.]
Zebrowski E.J., S. Pylypas, O. Odlum, and R.B. Johnson, J Periodont, 65:565, 1994