Figure 2: Leptin effect on NE-induced melatonin synthesis in cultured male rat pineal gland. The glands were challenged with different concentrations of leptin (Lep) (100 pM = 5 μM) associated with norepinephrine (NE) (1 μM). Melatonin values are expressed in ng/gland. One-way ANOVA, followed by Bonferroni's post hoc test. versus control, versus NE 1 μM. glands/group and each experiment was repeated 3 times.