Figure 7. Independent of dietary NaCl content NHE3^loxloxCre mice have lower Na⁺/phosphate co-transporter (Npt2a) and severely reduced Npt2c abundance.

NHE3 protein is absent in the kidney of NHE3^loxloxCre mice. In Con mice, NHE3 expression was unaffected in response to dietary NaCl. Phosphorylation of NHE3 at serine residue 552 was not affected by dietary NaCl in Con mice and, consistent with the absence of NHE3, barely detectable in NHE3^loxloxCre mice. Npt2a was unaffected by dietary NaCl in either genotype; however, significantly lower in NHE3^loxloxCre compared to Con mice. In Con mice, dietary NaCl has significant impact on Npt2c abundance. In contrast to Con mice, Npt2c is almost completely absent in NHE3^loxloxCre mice and not regulated by dietary NaCl. The Na⁺/bicarbonate cotransporter (NBCe1) was not affected by dietary NaCl or genotype. ND = not detectable. ^#P < 0.05 versus Con same diet.