Combined Effects of Lead and Zinc on Proliferation and Differentiation of osteoblasts in Newborn Rats

Objective: To investigate the effects of lead and zinc on proliferation and differentiation of osteoblasts in newborn rats.Methods: OsteobLasts were isolated from the calvaria of newborn rats and cultured in α-MEM medium.Lead and Zinc acetate with different concentration was administrated and cultivated for 48h.The proliferation response to lead and zinc was determined by MTT methods.The activity of alkaline phosphatase(ALP) was measured by alkaline phosphatase kit.Results: Treated with different levels of lead(10 μmol/L and 100 μmol/L) for 48h,the cell proliferation decreased(P0.05);Treated with zinc and lead for 48h,cell proliferation was higher than their single lead-treated group;differences were of statistical significance(P0.05) between the lead(1 μmol/L) plus zinc(50μmol/L),lead(10μmol/L) plus zinc(50μmol/L),lead(10μmol/L) plus zinc(100μmol/L) and control group.The activity of ALP was significantly decreased in group treated with a dose of 100 μmol/L lead for 48h(P0.05).When treated with zinc and lead for 48h,the activity of ALP was higher than their single lead-treated group;the ALP activity in groups of lead(1μmol/L,10μmol/L) plus zinc(50μmol/L) were higher than the control group,while that in group of lead(100 μmol/L) plus zinc(50 μmol/L) was significantly lower than the control group.All the difference was statistically significant(P0.05).Conclusions: There were adverse effects of lead on osteoblasts such as affecting their proliferation and differentiation.Zinc(50μmol/L) may have antagonistic joint action on lead in affec-ting the proliferation and differentiation of osteoblasts.Moreover,it also has a notable role on the activity of ALP.So it provides some proofs in preventing and curing lead poising bone diseases