Me. Peacock et al., THE EFFECT OF NICOTINE ON REPRODUCTION AND ATTACHMENT OF HUMAN GINGIVAL FIBROBLASTS IN-VITRO, Journal of periodontology, 64(7), 1993, pp. 658-665
THE ABILITY OF FIBROBLASTS TO REPRODUCE and attach to teeth is of para
mount importance in re-establishing the lost connective tissue attachm
ent after periodontal therapy. This study examined the effect of nicot
ine, a major component of the particulate phase of tobacco smoke, on h
uman gingival fibroblast (HGF) reproduction and attachment to tissue c
ulture surfaces. Pooled HGF cultures made from explants of gingival bi
opsies were utilized between passages 5 and 10 and plated in 96-well p
lates at 1.0 x 10(4) cells per well. Cell numbers were determined usin
g 3-(4,5-dimethylthiazol-2-y)-2,5-diphenyl tetrazolium bromide (MTT),
which is a reflection of mitochondrial dehydrogenase activity. The con
centrations of nicotine used were 0.025, 0.05, 0.1, 0.2, and 0.4 muM,
the average serum concentration for a smoker being approximately 0.1 m
uM. The effect of continuous nicotine exposure on HGF reproduction was
determined by incubating cell cultures and media containing nicotine
for up to 48 hours. Residual toxicity was determined by preincubating
cells with nicotine for 1 or 6 hours. HGF suspensions and increasing c
oncentrations of nicotine were added together to determine the effect
on attachment. Results showed an enhanced effect of nicotine on HGF at
tachment, with increasing numbers of cells attaching with increasing n
icotine concentrations, compared to the control. Low concentrations of
nicotine had a stimulatory effect on cell replication, while higher c
oncentrations of nicotine appear to have no significant effect on HGF
reproduction. The responses of cells to some concentrations of nicotin
e may persist after its removal.