Effect of nifedipine on the expression of bcl-2 protein in rat gingiva.

Bcl-2 is a family of proteins involved in protecting the cell against death stimuli or in promoting cell death. The aim of the present study was to determine the effect of nifedipine treatment on the expression of bcl-2 protein in rat gingival tissues. Rats were given gastric intubation with various concentrations and durations of nifedipine. Nifedipine-untreated and dimethylsulfoxide (DMSO)-treated animals served as control groups. The gingival tissues were dissected and the expression of bcl-2 protein was determined immunohistochemically. The results showed that the numbers of bcl-2-positive cells in the gingiva of nifedipine-treated animals were significantly higher than in the control groups. These numbers increased parallel to increased concentration and duration of nifedipine treatment. The results suggest that nifedipine treatment may induce the expression of bcl-2 protein in rat gingival tissue in a dose- and duration-dependent fashion and that this proto-oncogenic protein may play a role in nifedipine-induced gingival hyperplasia.