[Zinc promotes proliferation and differentiation of osteoblast in rats in vitro]

Effect of zinc on proliferation and differentiation of osteoblast in rats was studied in vitro.

Osteoblasts were isolated from the rat calvaria and subcultured in DMEM media. Rats were divided into four groups in the study, with administration of 0 micromol/L (as control), 10 micromol/L, 25 micromol/L and 50 micromol/L of Zn(2+), respectively. DNA synthesis at varied time points was determined with incorporation of (3)H-thymidine, and cell cycle was analyzed by flow cytometry. Synthesis of collagen was measured with incorporation of (3)H-proline. Activity of alkaline phosphatase (AKP) and osteocalcin content were measured by enzyme dynamics method and radioimmunoassay, respectively.

Incorporation of (3)H-thymidine in the three groups with different zinc-supplement was significantly higher than that in the control group at each time point, and supplement with 25 micromol/L and 50 micromol/L of Zn(2+) could promote the transition of cell cycle from phases G(0)/G(1) to S phase. Syntheses of collagen and osteocalcin and activity of AKP in the groups with zinc-supplement were greater, as compared with those in the control group.

Zinc could promote proliferation and differentiation of the rat osteoblast in vitro.