Nicotine Affects Proliferation and Differentiation of the Rabbit Osteoblasts in vitro and the Antagonistic Action of Vitamin C

Abstract: To study the effects of nicotine on the proliferation and differentiation of osteoblasts in neonatal rabbits and the antagonism of vitamin C in vitro， the issue cell culture method was used to isolate the rabbit osteoblasts. The cells were cultured with DMEM medium containing 10% fetal bovine serum with 0， 1×10-6， 1×10-5， 1 mmol/L nicotine and 0.5 mmol/L vitamin C+1 mmol/L nicotine for 1， 4， 7， 14 days. The cell proliferation was evaluated by MTT. The alkaline phosphatase (ALP) activity was estimated by PNPP. The expression of ALP， collagen type I (COLI) and osteocalcin (OCN) was estimated by reverse transcription-polymerase chain reaction (RT-PCR). ALP staining and Von Kossa staining are adopted to have a direct observation. The proliferation of neonatal rabbit osteoblasts was increased at 1×10-6， 1×10-5 mmol/L of nicotine， whereas inhibited at 1 mmol/L nicotine. ALP activity was increased at the same trend with proliferation. The expression of ALP， COLI and OCN was up-regulated at 1×10-6， 1×10-5 mmol/L of nicotine， while down-regulated at 1 mmol/L. The inhibition on proliferation and differentiation of 1 mmol/L nicotine group was antagonized partly by vitamin C. Nicotine had a two-phase effect on osteoblasts， showing as low level of nicotine could promote the proliferation and differentiation of the rabbit osteoblasts while the high level gets the opposite effect. Vitamin C could antagonize the inhibitory effect of higher concentration of nicotine on proliferation and differentiation of osteoblasts in part.

CSTR: 32200.14.cjcb.2012.02.0004