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Am J Physiol Renal Physiol
2013 Jul 15;3052:F208-15. doi: 10.1152/ajprenal.00185.2013.
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Inhibition of ROMK channels by low extracellular K+ and oxidative stress.
Frindt G
,
Li H
,
Sackin H
,
Palmer LG
.
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We tested the hypothesis that low luminal K⁺ inhibits the activity of ROMK channels in the rat cortical collecting duct. Whole-cell voltage-clamp measurements of the component of outward K⁺ current inhibited by the bee toxin Tertiapin-Q (ISK) showed that reducing the bath concentration ([K⁺]o) to 1 mM resulted in a decline of current over 2 min compared with that observed at 10 mM [K⁺]o. However, maintaining tubules in 1 mM [K⁺]o without establishing whole-cell clamp conditions did not affect ISK. The [K⁺]o-dependent decline was not prevented by increasing cytoplasmic-side pH or by inhibition of phosphatase activity. It was, however, abolished by the inclusion of 0.5 mM DTT in the pipette solution to prevent oxidation of the intracellular environment. Conversely, treatment of intact tubules with the oxidant H₂O₂ (100 μM) decreased ISK in a [K⁺]o-dependent manner. Treatment of the tubules with the phospholipase C inhibitor U73122 prevented the effect of low [K⁺]o, suggesting the involvement of this enzyme in the process. We examined these effects further using Xenopus oocytes expressing ROMK2 channels. A 50-min exposure to the permeant oxidizing agent tert-butyl hydroperoxide (t-BHP; 500 μM) did not affect outward K⁺ currents with [K⁺]o = 10 mM but reduced currents by 50% with [K⁺]o = 1 mM and by 75% with [K⁺]o = 0.1 mM. Pretreatment of the oocytes with U73122 prevented the effects of t-BHP. Under conditions of low dietary K intake, K⁺ secretion by distalnephron segments may be suppressed by a combination of low luminal [K⁺]o and oxidative stress.
Babilonia,
Superoxide anions are involved in mediating the effect of low K intake on c-Src expression and renal K secretion in the cortical collecting duct.
2005, Pubmed
Babilonia,
Superoxide anions are involved in mediating the effect of low K intake on c-Src expression and renal K secretion in the cortical collecting duct.
2005,
Pubmed
Babilonia,
Mitogen-activated protein kinases inhibit the ROMK (Kir 1.1)-like small conductance K channels in the cortical collecting duct.
2006,
Pubmed
Bannister,
The effects of oxidizing and cysteine-reactive reagents on the inward rectifier potassium channels Kir2.3 and Kir1.1.
1999,
Pubmed
,
Xenbase
Chen,
Modest dietary K+ restriction provokes insulin resistance of cellular K+ uptake and phosphorylation of renal outer medulla K+ channel without fall in plasma K+ concentration.
2006,
Pubmed
Choe,
A conserved cytoplasmic region of ROMK modulates pH sensitivity, conductance, and gating.
1997,
Pubmed
,
Xenbase
Cooper,
Renin-angiotensin-aldosterone system and oxidative stress in cardiovascular insulin resistance.
2007,
Pubmed
Dahlmann,
Regulation of Kir channels by intracellular pH and extracellular K(+): mechanisms of coupling.
2004,
Pubmed
,
Xenbase
Du,
Characteristic interactions with phosphatidylinositol 4,5-bisphosphate determine regulation of kir channels by diverse modulators.
2004,
Pubmed
,
Xenbase
Edvinsson,
Kir4.1 K+ channels are regulated by external cations.
2011,
Pubmed
,
Xenbase
Frindt,
Na channels in the rat connecting tubule.
2004,
Pubmed
Frindt,
Dietary K regulates ROMK channels in connecting tubule and cortical collecting duct of rat kidney.
2009,
Pubmed
,
Xenbase
Frindt,
Effects of dietary K on cell-surface expression of renal ion channels and transporters.
2010,
Pubmed
,
Xenbase
Frindt,
Conservation of Na+ vs. K+ by the rat cortical collecting duct.
2011,
Pubmed
Groschner,
Role of TRP channels in oxidative stress.
2004,
Pubmed
Huang,
Direct activation of inward rectifier potassium channels by PIP2 and its stabilization by Gbetagamma.
1998,
Pubmed
,
Xenbase
Kahle,
WNK4 regulates the balance between renal NaCl reabsorption and K+ secretion.
2003,
Pubmed
,
Xenbase
Kido,
Protective effect of dietary potassium against vascular injury in salt-sensitive hypertension.
2008,
Pubmed
Kiss,
Modulation of C-type inactivation by K+ at the potassium channel selectivity filter.
1998,
Pubmed
Kotchen,
Effects of NaCl on renin and aldosterone responses to potassium depletion.
1983,
Pubmed
Leung,
Phosphatidylinositol 4,5-bisphosphate and intracellular pH regulate the ROMK1 potassium channel via separate but interrelated mechanisms.
2000,
Pubmed
,
Xenbase
Levy,
A voltage-dependent role for K+ in recovery from C-type inactivation.
1996,
Pubmed
Lin,
Protein tyrosine kinase is expressed and regulates ROMK1 location in the cortical collecting duct.
2004,
Pubmed
Malnic,
Micropuncture study of distal tubular potassium and sodium transport in rat nephron.
1966,
Pubmed
Palmer,
Regulation of apical K and Na channels and Na/K pumps in rat cortical collecting tubule by dietary K.
1994,
Pubmed
Palmer,
Regulation of apical K channels in rat cortical collecting tubule during changes in dietary K intake.
1999,
Pubmed
Qin,
Activation and tyrosine phosphorylation of p72syk as well as calcium mobilization after hydrogen peroxide stimulation in peripheral blood lymphocytes.
1995,
Pubmed
Sackin,
Regulation of ROMK by extracellular cations.
2001,
Pubmed
,
Xenbase
Sackin,
Permeant cations and blockers modulate pH gating of ROMK channels.
2003,
Pubmed
,
Xenbase
Sackin,
Potassium-dependent slow inactivation of Kir1.1 (ROMK) channels.
2004,
Pubmed
,
Xenbase
Schulte,
pH-dependent gating of ROMK (Kir1.1) channels involves conformational changes in both N and C termini.
1998,
Pubmed
,
Xenbase
Schulte,
K(+)-dependent gating of K(ir)1.1 channels is linked to pH gating through a conformational change in the pore.
2001,
Pubmed
,
Xenbase
Silva,
Adaptation to potassium.
1977,
Pubmed
Smith,
Receptor-coupled signal transduction in human polymorphonuclear neutrophils: effects of a novel inhibitor of phospholipase C-dependent processes on cell responsiveness.
1990,
Pubmed
Sterling,
Tetanus toxin abolishes exocytosis of ROMK1 induced by inhibition of protein tyrosine kinase.
2003,
Pubmed
Vallon,
Expression and phosphorylation of the Na+-Cl- cotransporter NCC in vivo is regulated by dietary salt, potassium, and SGK1.
2009,
Pubmed
Wade,
Differential regulation of ROMK (Kir1.1) in distal nephron segments by dietary potassium.
2011,
Pubmed
Wang,
Oxidative stress-induced phospholipase C-gamma 1 activation enhances cell survival.
2001,
Pubmed
Wang,
Regulation of small-conductance K+ channel in apical membrane of rat cortical collecting tubule.
1990,
Pubmed
Wei,
Angiotensin II inhibits the ROMK-like small conductance K channel in renal cortical collecting duct during dietary potassium restriction.
2007,
Pubmed
Wei,
Effect of hydrogen peroxide on ROMK channels in the cortical collecting duct.
2007,
Pubmed
Wei,
Effect of dietary K intake on apical small-conductance K channel in CCD: role of protein tyrosine kinase.
2001,
Pubmed
Weinstein,
A mathematical model of rat cortical collecting duct: determinants of the transtubular potassium gradient.
2001,
Pubmed
Wilcox,
Oxidative stress and nitric oxide deficiency in the kidney: a critical link to hypertension?
2005,
Pubmed
Yang,
Increased superoxide anion generation and altered vasoreactivity in rabbits on low-potassium diet.
1998,
Pubmed
Zeng,
Evidence for endocytosis of ROMK potassium channel via clathrin-coated vesicles.
2002,
Pubmed
,
Xenbase
Zhang,
Localization of the pH gate in Kir1.1 channels.
2006,
Pubmed
,
Xenbase
Zhou,
Chemistry of ion coordination and hydration revealed by a K+ channel-Fab complex at 2.0 A resolution.
2001,
Pubmed
