HO-1 mRNA and protein expression in tissues was highly induced under normal condition by VitC. A) HO-1 mRNA in the kidney (a), liver (b), and lung (c) are expressed relative to the level measured in the control animals. B) HO-1 protein expression in the kidney (a), liver (b), and lung (c) were detected using Western-blot. Each gel is representative of six independent experiments. Densitometric analysis was used to calculate the normalized protein ratio (HO-1 to β-actin). C) distribution of HO-1 protein in the kidney (a, d, scale bar: 200 μm), liver (b, e, scale bar: 100 μm), and lung (c, f, scale bar: 200 μm) were demonstrated by immunohistochemistry. The arrowheads indicate the HO-1-positive cells. Each image is representative of six independent experiments (n = 6). Tissue samples were collected at 2, 6, 12 and 24 hours after VitC treatment. Data represent the mean ± SEM. *p < 0.05 vs. the control. Control: normal saline-treated rats. V6h: the rats treated with VitC for 6 hrs.