Fig. 7.

Immunohistochemistry of NHE8 in 1-day-old (A), 10-day-old (B), and adult (C) rat kidney. NHE8 is costained with villin (brush border), Lotus tetragonolobus agglutinin (LTA, proximal tubule), and Na⁺/Ca²⁺ exchanger (NCX-1, distal tubule). Superficial cortex is shown at top of the low-magnification figures stained for NHE8 alone. Nephrogenic zone is still present in 1-day-old neonates (A, left). In low magnification of developing kidney, NHE8 staining is most intense, but not limited to proximal tubule. Although it is likely that this staining represents background, we cannot rule out expression in other nephron segments. NHE8 staining appears to be heterogeneous on apical membrane of proximal tubules, and NHE8 labeling may be limited to certain segments of proximal tubule in neonatal and adult kidney. Scale bars, 50 μm.