Fig. 2.

Estradiol regulates aromatase mRNA expression and enzyme activity in N42, but not N38, hypothalamic cells. A) Real-time RT-PCR was performed to measure aromatase mRNA expression after 6, 12, and 24 h of E₂ (10⁻⁷ M) treatment. Aromatase mRNA levels were normalized to Gapdh mRNA levels. Results are expressed as the mean ± SEM (n = 3); **P < 0.01, paired t-test. Aromatase activity assays were performed in N42 (B) and N38 (C) hypothalamic cells after 6, 12, and 24 h of E₂ (10⁻⁷ M) treatment. The results are expressed as the mean ± SEM (n = 3); **P < 0.01, paired t-test. Aromatase enzyme activity in each neuronal line treated with the aromatase enzyme inhibitor letrozole (LET) was undetectable (data not shown).