Dynamics of Akt phosphorylation under different concentrations of niacin.

<p>CHO-HCA₂ (A), A431 (B) or CHO-HCA₃(C) cells were plated on 24-well plates with DMEM/F-12 or DMEM. 12 hours later, the medium was changed to serum-free DMEM/F-12 or DMEM. After overnight starvation, all the cells were treated with different concentrations of niacin for 5 min. Akt phosphorylation at both Ser⁴⁷³ and Thr³⁰⁸ were detected by Immunobloting. Primary macrophages (D), isolated from 4–6 week old mice, were plated on 24-well plates with modified (RPMI)-1640 medium overnight. Cells were then starved for 3 h and stimulated with 400 µM niacin for different times. Akt phosphorylation at Ser⁴⁷³ was detected by Immunobloting. WT: wild type mouse. The data shown are representative of at least three independent experiments. The data were analyzed using Student’s t test (*, p<0.05; **, p<0.01; ***, p<0.001).