NDT Advance Access originally published online on February 17, 2007
Nephrology Dialysis Transplantation 2007 22(5):1305-1308; doi:10.1093/ndt/gfm010
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© The Author [2007]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org
WNK4, as thiazides, shuts off NaCl reabsorption to stimulate Na/K exchange*
Institute of Physiology and Centre for Integrative Human Physiology (ZIHP), University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
Correspondence and offprint requests to: François Verrey, Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. Email: verrey@access.unizh.ch
Keywords: aldosterone; arterial blood pressure; distal convoluted tubule; Familial hyperkalemic hypertension; Gordon's syndrome; K+ secretion; NaCl reabsorption; thiazides
| The first 150 words of the full text of this article appear below. |
In a manuscript recently published in Nature Genetics, Lalioti et al. [1] show that Wnk4 switches distal nephron function from NaCl reabsorption to Na+/K+ exchange, mainly by dismantling the NaCl cotransporter expressing distal convoluted tubule segment DCT1. Interestingly, the structural integrity of this segment had already been shown long ago to depend on NaCl cotransporter function, as thiazides provoke similar DCT1 regression as Wnk4 overexpression [2].
The observation underlying the study by Lalioti et al. is that the rare autosomal dominant form of arterial hypertension Familial hyperkalemic hypertension (FHHt), also called Pseudohypoaldosteronism type II (PHAII) or Gordon's Syndrome, is caused by mutations in the gene encoding the protein kinase WNK1 or WNK4 [3]. The salient feature of FHHt is the unusual combination of Na+ and K+ retention. Additional symptoms are hyperchloraemia and metabolic acidosis. The central physiological question that is
| Transgenic mice expressing wild-type or FHHt mutant Wnk4 |
|---|
| Inhibition of NCC by Wnk4 triggers dismantling of the DCT1 nephron segment |
|---|
| Do the other Wnk4 functions described in vitro play a physiological role? |
|---|
| Conclusions |
|---|