Effect of 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) enantiomers, major metabolites of phenytoin, on the occurrence of chronic-gingival hyperplasia: in vivo and in vitro study
✍ Scribed by I. Ieiri; W. Goto; S. Higuchi; K. Hirata; A. Toshitani; S. Imayama; Y. Ohyama; H. Yamada; K. Ohtsubo
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 571 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0031-6970
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✦ Synopsis
The purpose of this study was to assess the possible role of the (R)-and (S)-enantiomers of the phenytoin metabolite p-HPPH in the pathogenesis of gingival hyperplasia (GH). About 98% of circulating p-HPPH is in the (S)-form. There were significant differences between patients with and without GH in (R)-p-HPPH level (0.055 vs 0.042 gg. ml-l), both enantiomer/racemate level ratios, and R/S enantiomeric ratio (0.0313 vs 0.0232); an increase in serum (R)-p-HPPH level was observed in patients with GH. In separate experiments, the effect of p-HPPH enantiomers on the proliferation of the normal human dermal fibroblast was studied. The in vitro study showed that (R)-p-HPPH selectively stimulated fibroblast growth. The results suggest that the least abundant metabolite, (R)-p-HPPH, is the most toxic with respect to gingival hyperplasia.