Hydroxyproline and total protein levels in gingiva from patients treated with phenytoin and cyclosporine-A.

Hydroxyproline (Hyp) and total protein levels were studied in gingiva from patients treated with phenytoin (PHT) and cyclosporine-A (CSA). The study included 5 groups of subjects: PHT and CSA groups with and without gingival overgrowth (PHT-GO+), (PHT-GO-), (CSA-GO+), (CSA-GO-), and periodontally healthy controls (C). After taking clinical measurements, gingival samples were harvested by gingivectomy or excising one or two papillae from the posterior areas. The samples were analyzed biochemically. In the PHT groups, both Hyp and total protein levels were significantly higher than in the C group. The differences between the PHT-GO+ and PHT-GO- groups were not statistically significant. In the CSA groups, total protein levels were significantly higher than in controls while no significant difference was found in Hyp levels. The differences between the CSA-GO+ and CSA-GO- groups were not statistically significant. When the PHT and CSA groups were compared, Hyp levels were significantly higher in the PHT-GO+ group than in the CSA-GO+ group. Total protein level differences between the PHT and CSA groups were not statistically significant. Correlations between age, plaque index, gingival overgrowth index, Hyp and total protein levels were analyzed and most were found not to be statistically significant. PHT appears to stimulate both collagen and total protein synthesis in gingiva while CSA seems to have a stronger effect on total protein synthesis. This suggests that the mechanisms underlying PHT- and CSA-induced gingival overgrowth are different and further comparative studies are needed.