Fig. 5

rhFGF21 improves the impaired antioxidant activities of kidney in mice treated with DOCA-salt. Eight-week-old male FGF21 WT mice were randomly divided into three experimental groups: the WT-Control group treated with sham operation, followed by intraperitoneal injection with 0.9% normal saline; the WT-DOCA group treated with DOCA-salt; the WT-DOCA-FGF21 group treated with DOCA-salt, followed by intraperitoneal supplementation of recombinant human FGF21 (rhFGF21, 500 μg/kg/day body weight). Serum and kidney tissues were harvested at 8 days after intervention. a and b Kidney sections were collected and stained with antibody against HO-1 and NQO-1 and the quantitative mean integrated optical density (IOD)/area of HO-1 and NQO-1 were analyzed by Image-Pro plus 6.0 in each group were shown. c Protein expressions of HO-1 and NQO-1 were determined by Western blot. GAPDH was used as loading and normalization control and the quantifications of protein expressions of HO-1 and NQO-1 were analyzed by Image J. d and e Effects of rhFGF21 on malonyldialdehyde (MDA) and superoxide dismutase (SOD) levels of kidney tissues at 8 days after DOCA-salt treatment. f and g Serum levels of MDA and SOD were measured at 8d after DOCA-salt treatment in each group. Data are presented as Mean ± SD, n = 5–6 mice/group. *P < 0.05, **P < 0.01 versus the WT control group; ^#P < 0.05, ^##P < 0.01 versus the WT-DOCA group. Scale bar: 100 μm