Induction of

Ngb mRNA expression by hemin. (A) HN33 cells were treated with hemin at the indicated concentrations for 24 hours and RT-PCR was used to detect Ngb mRNA expression (left), which was quantified by computer densitometry and normalized to the expression of β-actin (right). *P < .05, **P < .001 compared with 0 μM. (B) HN33 cells were treated with 50 μM hemin for the indicated times, and RT-PCR was used to detect Ngb mRNA expression (left), which was quantified by computer densitometry and normalized to the expression of β-actin (right). *P < .05, **P < .001 compared with 0 hours. (C) HN33 cells were treated with 50 μM hemin for the indicated times and Northern blotting was used to detectNgb mRNA expression (left), which was quantified by computer densitometry and normalized to the expression of β-actin (right). Data are representative blots (left) or mean ± SEM (right) from 3 experiments. *P < .001 compared with 0 hours.