0628 Verapamil Enhances the Apoptosis of Gingival Fibroblasts in vitro
Q.X. LUAN, and C.F. CAO, Peking University School of Stomatology, Beijing, China

Objective:To evaluate the effect of verapamil, a calcium channel blocker, on the apoptosis of gingival fibroblasts in vitro. Methods:Gingival biopsy specimens were obtained from 4 periodontally healthy donors and 2 nifedipine-induced gingival hyperplasia patients. Gingival fibroblasts were isolated and cultured from normal gingiva(NGFs) and hyperplastic tissue(HGFs) by tissue fragment culture method. The 4th passage of NGFs and HGFs at a concentration of 105cells/ml were incubated without verapamil (blank) and with 0.1µM, 1µM, 10µM, 100µM verapamil, respectively, for 18h. All treatments were performed in duplicate. After staining with annexin V-FITC and propidium iodide(PI), the apoptosis of GFs were assessed by fluorescent microscope and flow cytometry. Results:Apoptosis of both NGFs and HGFs in cultures with or without verapamil were confirmed under fluorescent microscope. The percentages of apoptotic cells in normal gingival fibroblasts(NGFs) were as follows: 12.7% in blank group, 18.8% in 0.1µM verapamil, 16.9% in 1µM verapamil, 20.9% in 10µM verapamil and 24.3% in 100µM verapamil group. The percentage of apoptotic HGF in 0.1µM and 1.0µM verapamil groups were 18.8% and 20.1%, respectively, similar to that in blank group(22.5%). However, the percentages of apoptotic HGF in 10µM and 100µM verapamil groups reached 39.6% and 31.4%. Among the apoptotic cells, HGFs showed higher proportion of early stage apoptosis than NGFs in blank and all verapamil groups. These results indicated: There was a natural apoptosis of both cell lines in vitro. The apoptotic extent of NGFs increased with increasing verapamil concentrations. However, only high concentration verapamil (10µM and 100µM) could enhance the apoptosis of HGFs. Conclusion:Verapamil enhances the apoptosis of NGF and HGF in vitro. NGF and HGF showed different patterns in apoptotic response to verapamil.

Seq #71 - Oral Tissues, Pharmacology
11:00 AM-12:15 PM, Thursday, 26 June 2003 Svenska Massan Exhibition Hall B

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