Fig. 2.

SP increases preadipocyte proliferation via Akt and PKC-θ-dependent mechanisms. A: serum-starved human mesenteric preadipocytes were exposed to TFA (vehicle) or a specific PKC-θ inhibitor, Akt inhibitor V, or the neurokinin-1 receptor (NK-1R) antagonist CJ 012,255 (CJ) with SP (10⁻⁷ M) for 8 h. Cells were then incubated with bromodeoxyuridine, and color changes were recorded at an absorbance of 450 nm. Data are expressed as means ± SE. **P < 0.01 vs. all other groups. C, control. B and C: SP induces Akt and PKC-θ phosphorylation in human mesenteric preadipocytes. Serum-starved human mesenteric preadipocytes were exposed to SP (10⁻⁷ M) or SP + CJ 012,255 for the indicated times. Cells were lysed, and equal amounts of protein were fractionated by SDS/12.5% PAGE to determine the levels of phospho-Akt (B), phospho-PKC-θ (C), and GAPDH (B and C).