Fig. 6.

Effect of acid loading on Rhbg expression in IC-Rhbg-KO mice. A: immunoblot analyses of Rhbg expression in IC-Rhbg-KO mice fed control diet (powdered rodent chow + H₂O) or acid-loading diet (powdered rodent chow + HCl, 0.4 M). B: quantified Rhbg expression. IC-Rhbg-KO mice show a time-dependent, progressive increase in Rhbg expression in both the cortex and the outer medulla, while expression in the inner medulla does not change significantly. C: immunolocalization of Rhbg in the CCD of IC-Rhbg-KO mice on control diet and after 5-day HCl acid loading. Double immunolabel for H⁺-ATPase (blue) and Rhbg (brown) was used to differentiate intercalated and principal cells. Intercalated cells (arrowheads) lack Rhbg expression; acid loading increases Rhbg immunolabel in principal cells (arrows). D: same pattern of expression in the OMCD. Acid loading increases principal cell (arrows) Rhbg immunolabel.