A study of tubular potassium secretory capacity in older patients with hyperkalaemia

Greevy, C Mc; Horan, John J.; Jones, D.A.; Biswas, Kaushik; O'Meara, Y M; Mulkerrin, E.

doi:10.1007/bf02982569

Cited by 6 publications

(5 citation statements)

References 10 publications

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“…The TTKG, used frequently in previous studies [6;15–17], was used in this study as a determination of K secretion in the CNT and initial CCD. The accuracy of this approach may be open to question, especially in view of the likelihood of K reabsorption along the collecting ducts (CD).…”

Section: Discussionmentioning

confidence: 99%

Relation between BK-α/β4-mediated potassium secretion and ENaC-mediated sodium reabsorption

Wen

Cornelius

Rivero-Hernandez

et al. 2014

Kidney International

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The large conductance, calcium-activated BK-α/β4 potassium channel, localized to the intercalated cells of the distal nephron, mediates potassium secretion during high potassium, alkaline diets. Here we determine whether BK-α/β4-mediated potassium transport is dependent on epithelial sodium channel (ENaC)-mediated sodium reabsorption. We maximized sodium-potassium exchange in the distal nephron by feeding mice a low sodium, high potassium diet. Wild type and BK-β4 knockout mice were maintained on low sodium, high potassium, alkaline diet or a low sodium, high potassium, acidic diet for 7–10 days. Wild type mice maintained potassium homeostasis on the alkaline but not acid diet. BK-β4 knockout mice could not maintain potassium homeostasis on either diet. During the last 12 hours of diet, wild type mice on either a regular, alkaline or an acid diet, or knockout mice on an alkaline diet were administered amiloride (an ENaC inhibitor). Amiloride enhanced sodium excretion in all wild type and knockout groups to similar values; however, amiloride diminished potassium excretion by 59% in wild type but only by 33% in knockout mice on an alkaline diet. Similarly, amiloride decreased the transtubular potassium gradient by 68% in wild type but only by 42% in knockout mice on an alkaline diet. Amiloride treatment equally enhanced sodium excretion and diminished potassium secretion in knockout mice on an alkaline diet and wild type mice on an acid diet. Thus, the enhanced effect of amiloride on potassium secretion in wild type compared to knockout mice on the alkaline diet, clarify a BK- α/β4-mediated potassium secretory pathway in intercalated cells driven by ENaC-mediated sodium reabsorption linked to bicarbonate secretion.

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Section: Discussionmentioning

confidence: 99%

Relation between BK-α/β4-mediated potassium secretion and ENaC-mediated sodium reabsorption

Wen

Cornelius

Rivero-Hernandez

et al. 2014

Kidney International

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“…It was found that the maximum urinary osmolality decreased by approximately 20% in the 60-79 age group compared to the 20-39 age group (Rowe et al, 1976). At the same time, the ability of aging kidneys to reabsorb sodium and excrete potassium is significantly reduced, leading to a predisposition to water-electrolyte disorders in the elderly (McGreevy et al, 2008;Mimran et al, 1992).…”

Section: Physiological Characteristicsmentioning

confidence: 99%

Biomarkers of aging

Bao

Cao

Chen

et al. 2023

Sci. China Life Sci.

153

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Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant. Supporting Information The supporting information is available online at 10.1007/s11427-023-2305-0. The supporting materials are published as submitted, without typesetting or editing. The responsibility for scientific accuracy and content remains entirely with the authors.

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“…[21][22][23] Elderly patients show decreased transtubular potassium gradients and fail to increase distal tubule potassium excretion when hyperkalemic or in response to fludrocortisone. 24 Decreased potassium excretion correlates with decreasing GFR and may reflect a degree of reduced sodium and chloride delivery to the distal convoluted tubule. 25…”

Section: Decreased Tubular Functionmentioning

confidence: 99%

Renal Aging: Causes and Consequences

O’Sullivan

Hughes

Ferenbach

2016

JASN

382

307

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Individuals age >65 years old are the fastest expanding population demographic throughout the developed world. Consequently, more aged patients than before are receiving diagnoses of impaired renal function and nephrosclerosis-age-associated histologic changes in the kidneys. Recent studies have shown that the aged kidney undergoes a range of structural changes and has altered transcriptomic, hemodynamic, and physiologic behavior at rest and in response to renal insults. These changes impair the ability of the kidney to withstand and recover from injury, contributing to the high susceptibility of the aged population to AKI and their increased propensity to develop subsequent progressive CKD. In this review, we examine these features of the aged kidney and explore the various validated and putative pathways contributing to the changes observed with aging in both experimental animal models and humans. We also discuss the potential for additional study to increase understanding of the aged kidney and lead to novel therapeutic strategies.

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A study of tubular potassium secretory capacity in older patients with hyperkalaemia

Cited by 6 publications

References 10 publications

Relation between BK-α/β4-mediated potassium secretion and ENaC-mediated sodium reabsorption

Relation between BK-α/β4-mediated potassium secretion and ENaC-mediated sodium reabsorption

Biomarkers of aging

Renal Aging: Causes and Consequences

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