Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro

To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms. Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting. Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment wi