Fig. 3.

17β-estradiol time dependently induces Akt, but not ERK1/2 phosphorylation. Astrocyte cultures were treated with 17β-estradiol (10 nM) for 0, 5, 15, 30, 60, and 120 min after which protein was collected. A: Western blot analysis of pure astrocyte cultures shows an increase in Akt phosphorylation starting at 5 min and extending through 60 min. B: 17β-estradiol did not significantly activate pERK1/2 at any of the time points. C: 17β-estradiol induced activation of pAkt at 30 min was blocked by co administration of the PI3K inhibitor LY294002. No change was observed in total AKT or total ERK1/2, which served as loading controls. Results are from a single experiment and are representative of at least three independent experiments. *p < 0.05 versus control astrocytes.