| First Author | Poulsen SB | Year | 2016 |
| Journal | Am J Physiol Renal Physiol | Volume | 310 |
| Issue | 4 | Pages | F300-10 |
| PubMed ID | 26582762 | Mgi Jnum | J:282698 |
| Mgi Id | MGI:6367931 | Doi | 10.1152/ajprenal.00258.2015 |
| Citation | Poulsen SB, et al. (2016) Reducing alphaENaC expression in the kidney connecting tubule induces pseudohypoaldosteronism type 1 symptoms during K+ loading. Am J Physiol Renal Physiol 310(4):F300-10 |
| abstractText | Genetic inactivation of the epithelial Na(+) channel alpha-subunit (alphaENaC) in the renal collecting duct (CD) does not interfere with Na(+) and K(+) homeostasis in mice. However, inactivation in the CD and a part of the connecting tubule (CNT) induces autosomal recessive pseudohypoaldosteronism type 1 (PHA-1) symptoms in subjects already on a standard diet. In the present study, we further examined the importance of alphaENaC in the CNT. Knockout mice with alphaENaC deleted primarily in a part of the CNT (CNT-KO) were generated using Scnn1a(lox/lox) mice and Atp6v1b1::Cre mice. With a standard diet, plasma Na(+) concentration ([Na(+)]) and [K(+)], and urine Na(+) and K(+) output were unaffected. Seven days of Na(+) restriction (0.01% Na(+)) led to a higher urine Na(+) output only on days 3-5, and after 7 days plasma [Na(+)] and [K(+)] were unaffected. In contrast, the CNT-KO mice were highly susceptible to a 2-day 5% K(+) diet and showed lower food intake and relative body weight, lower plasma [Na(+)], higher fractional excretion (FE) of Na(+), higher plasma [K(+)], and lower FE of K(+). The higher FE of Na(+) coincided with lower abundance and phosphorylation of the Na(+)-Cl(-) cotransporter. In conclusion, reducing ENaC expression in the CNT induces clear PHA-1 symptoms during high dietary K(+) loading. |
