Low Dietary Potassium Causes Direct Kidney Injury
Diets with a high sodium-to-potassium ratio are linked to poor cardiovascular outcomes. Attention has mostly focused on high sodium, but low potassium is also a culprit in cardiovascular disease.
Andrew Terker, MD, PhD, and colleagues have now discovered that low dietary potassium also causes direct kidney injury.
Using in vitro and in vivo approaches, the researchers demonstrated that the injury effects depend on the Kir4.2 potassium channel in kidney proximal tubule cells. Efflux of potassium from the cells caused intracellular acidosis and activated the enzyme glutaminase, leading to hypertrophy, inflammation and fibrosis. Deletion of Kir4.2 or glutaminase protected proximal tubule cells from injury in both cell culture and animal models.
The findings, published in Cell Reports, identify Kir4.2 and glutaminase as mediators of low potassium-related kidney injury and potential therapeutic targets. The findings also suggest that the standard practice of recommending excessive restriction of dietary potassium for patients with chronic kidney disease could unintentionally contribute to disease progression in certain settings.
Reference: Terker AS, Zhang Y, Arroyo JP, et al. Kir4.2 mediates proximal potassium effects on glutaminase activity and kidney injury. Cell Reports. 2022;41(12). doi:10.1016/j.celrep.2022.111840
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