Fig. 4

Effect of iron administration on the relative mRNA levels of HIF-1α (A), Heme Oxygenase 1 (HMOX1) (B), and NAD(P)H quinone dehydrogenase 1 (NQO1) (C) in the adenine-treated rats fed a high-phosphate diet and the correlations between aortic Nrf2 mRNA levels and HIF-1α mRNA levels (R = 0.65, p = 0.013) (D), between aortic ferritin H mRNA levels and HIF-1α mRNA levels (R = 0.83, p = 0.0002) (E), between aortic Nrf2 mRNA levels and HMOX1 mRNA levels (R = 0.56, P = 0.035) (F), and between aortic Nrf2 mRNA levels and NQO1 mRNA levels (R = 0.95, P = 0.000002) (G). The No-Fe group, PO-Fe group and IP-Fe group were CKD rats without Fe administration, with peroral Fe administration and with intraperitoneal Fe administration, respectively. Data are expressed as the mean ± SD and were compared by one-way analysis of variance followed by the Tukey–Kramer test. Linear regression analyses were used to determine the correlations between parameters. A two-tailed p < 0.05 was considered statistically significant