Figure 4. Melatonin increases the expression of p-AKT and this effect could be suppressed by Wortmannin and luzindole. Wortmannin is a non-specific, covalent inhibitor of PI3K. luzindole acts as a selective melatonin receptor antagonist for the MT2 receptor. A 30 min preincubation step with the PI3K inhibitor Wortmannin (100 nM) or a 60 min preincubation step with the MT2 receptor antagonist Luzindole (1 μM) was included before melatonin stimulation. (A) Melatonin receptors MT1 and MT2 were detected in megakaryocytic CHRF cells through Western Blot. L-02 cells was the positive control. P-AKT was also detected by Western Blot. Cells were treated with (B) melatonin (200 nM), wortmannin (100 nM) or melatonin+wortmannin and (C) melatonin (200 nM), luzindole (1 μM) or melatonin+luzindole. Two-way ANOVA (with a Tukey multiple comparison test) was employed to test for significance. * p< 0.05, ** p< 0.01, n=5.