Distal potassium handling based on flow modulation of maxi-K channel activity

Aylin R Rodan; Chou-Long Huang

doi:10.1097/MNH.0b013e32832c75d8

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Distal potassium handling based on flow modulation of maxi-K channel activity

Journal article

Peer reviewed

Distal potassium handling based on flow modulation of maxi-K channel activity

Aylin R Rodan and Chou-Long Huang

Current opinion in nephrology and hypertension, Vol.18(4), pp.350-355

07/2009

DOI: 10.1097/MNH.0b013e32832c75d8

PMCID: PMC3151167

PMID: 19448535

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Abstract

Studies on the mechanisms of distal K+ secretion have highlighted the importance of the renal outer-medullary K+ (ROMK) and maxi-K channels. This review considers several human disorders characterized by hypokalemia and hyperkalemia, as well as mouse models of these disorders, and the mechanisms by which ROMK and maxi-K may be dysregulated. Analysis of knockout mice lacking ROMK, a model for type II Bartter's syndrome, has shown a role for maxi-K in distal K+ secretion. Knockout mice lacking either the alpha or beta1 subunits of maxi-K also show deficits in flow-dependent K+ secretion. Analysis of transgenic and knock-in mouse models of pseudohypoaldosteronism type II, in which mutant forms of with-no-lysine kinase 4 are expressed, suggests ways in which ROMK and maxi-K may be dysregulated to result in hyperkalemia. Modeling studies also provide insights into the role of Na+ delivery vs. flow in K+ secretion. The importance of both ROMK and maxi-K to distal K+ secretion is now well established, but the relative role that each of these two channels plays in normal and diseased states has not been definitively established. Analysis of human and animal model data can generate hypotheses for future experiments.

Potassium - metabolism

Animals

Large-Conductance Calcium-Activated Potassium Channels - physiology

Protein-Serine-Threonine Kinases - physiology

Humans

Kidney Medulla - metabolism

Bartter Syndrome - etiology

Pseudohypoaldosteronism - metabolism

Sodium - metabolism

Kidney Tubules, Distal - metabolism

Sodium Chloride Symporters - physiology

Details

Title: Subtitle: Distal potassium handling based on flow modulation of maxi-K channel activity
Creators: Aylin R Rodan - Division of Nephrology, Department of Medicine, UT Southwestern Medical Center, Dallas, Texas 75390-8856, USA. aylin.rodan@utsouthwestern.edu
Chou-Long Huang
Resource Type: Journal article
Publication Details: Current opinion in nephrology and hypertension, Vol.18(4), pp.350-355
DOI: 10.1097/MNH.0b013e32832c75d8
PMID: 19448535
PMCID: PMC3151167
NLM abbreviation: Curr Opin Nephrol Hypertens
ISSN: 1062-4821
eISSN: 1473-6543
Grant note: R01 DK059530 / NIDDK NIH HHS DK-59530 / NIDDK NIH HHS R01 DK059530-08 / NIDDK NIH HHS
Language: English
Date published: 07/2009
Academic Unit: Nephrology; Internal Medicine
Record Identifier: 9984094611902771

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