Essential role of Kir5.1 channels in renal salt handling and blood pressure control

Oleg Palygin, Vladislav Levchenko, Daria V. Ilatovskaya, Tengis S. Pavlov, Oleh M. Pochynyuk, Howard J. Jacob, Aron M. Geurts, Matthew R. Hodges, Alexander Staruschenko

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Supplementing diets with high potassium helps reduce hypertension in humans. Inwardly rectifying K+ channels Kir4.1 (Kcnj10) and Kir5.1 (Kcnj16) are highly expressed in the basolateral membrane of distal renal tubules and contribute to Na+ reabsorption and K+ secretion through the direct control of transepithelial voltage. To define the importance of Kir5.1 in blood pressure control under conditions of salt-induced hypertension, we generated a Kcnj16 knockout in Dahl salt-sensitive (SS) rats (SSKcnj16–/–). SSKcnj16–/– rats exhibited hypokalemia and reduced blood pressure, and when fed a high-salt diet (4% NaCl), experienced 100% mortality within a few days triggered by salt wasting and severe hypokalemia. Electrophysiological recordings of basolateral K+ channels in the collecting ducts isolated from SSKcnj16–/– rats revealed activity of only homomeric Kir4.1 channels. Kir4.1 expression was upregulated in SSKcnj16–/– rats, but the protein was predominantly localized in the cytosol in SSKcnj16–/– rats. Benzamil, but not hydrochlorothiazide or furosemide, rescued this phenotype from mortality on a high-salt diet. Supplementation of high-salt diet with increased potassium (2% KCl) prevented mortality in SSKcnj16–/– rats and prevented or mitigated hypertension in SSKcnj16–/– or control SS rats, respectively. Our results demonstrate that Kir5.1 channels are key regulators of renal salt handling in SS hypertension.

Original languageEnglish (US)
Article numbere92331
JournalJCI Insight
Volume2
Issue number18
DOIs
StatePublished - Sep 21 2017
Externally publishedYes

ASJC Scopus subject areas

  • Medicine(all)

Fingerprint

Dive into the research topics of 'Essential role of Kir5.1 channels in renal salt handling and blood pressure control'. Together they form a unique fingerprint.

Cite this