Fig. 2.

Effects of PI3K inhibition and melatonin receptor blockade on melatonin-induced Akt phosphorylation. Melatonin (10µM) was applied to primary cultures for 12 hr in the absence or presence of wortmannin or luzindole. Concentrations and preincubation times of these compounds were as follows: wortmannin (W), 10µM, 1 hr; luzindole (L), 100µM, 1 hr. Right panel represents quantitative analysis. The phospho-Akt/Akt ratio was determined and expressed as mean±SEM. Akt phosphorylation by melatonin was inhibited by pretreatment of the cells with wortmannin or luzindole. ^*p<0.05 and ^**p<0.01 indicate statistically significant difference from the melatonin treated group.