Figure 3

Tolvaptan induces Nrf2 nuclear translocation and HO-1 expression in vivo. (a) Tolvaptan promotes Nrf2 nuclear translocation in the outer medulla of mouse kidneys. (Top panel) Male C57BL/6J mice aged 8–9-weeks were fed with a diet containing 0.5% tolvaptan for 24 h. The nuclear extract was obtained from the outer medulla. Arrow indicates the band of Nrf2. (Bottom panel) Nrf2 bands were quantified using densitometric analysis. Bar indicates average from four or five experiments (control: n = 4, tolvaptan: n = 5). Student’s t-test, **P < 0.01. C: control, Tol: 0.5% tolvaptan. (b) Tolvaptan increases HO-1 protein expression in the outer medulla of mouse kidneys. (Top panel) Tolvaptan (0.5%) was administered via diet to 8–9-week-old male C57BL/6J mice for 24 h. The kidneys were separated into the cortex and the outer medulla, and the whole protein extraction was performed. The blots of HO-1 and Actin were configured with the blot of cortex and that of outer medulla. Fractionation of the cortex and the outer medulla was verified using UMOD and pNCC antibodies. (Bottom panel) Densitometric analysis of HO-1 is shown. Bar indicates average from four or five experiments (control: n = 4, tolvaptan: n = 5). Student’s t-test, *P < 0.05. C: control, Tol: 0.5% tolvaptan.