Accéder au contenu
Merck

Effects of extreme potassium stress on blood pressure and renal tubular sodium transport.

American journal of physiology. Renal physiology (2020-04-14)
Cary R Boyd-Shiwarski, Claire J Weaver, Rebecca T Beacham, Daniel J Shiwarski, Kelly A Connolly, Lubika J Nkashama, Stephanie M Mutchler, Shawn E Griffiths, Sophia A Knoell, Romano S Sebastiani, Evan C Ray, Allison L Marciszyn, Arohan R Subramanya
RÉSUMÉ

We characterized mouse blood pressure and ion transport in the setting of commonly used rodent diets that drive K+ intake to the extremes of deficiency and excess. Male 129S2/Sv mice were fed either K+-deficient, control, high-K+ basic, or high-KCl diets for 10 days. Mice maintained on a K+-deficient diet exhibited no change in blood pressure, whereas K+-loaded mice developed an ~10-mmHg blood pressure increase. Following challenge with NaCl, K+-deficient mice developed a salt-sensitive 8 mmHg increase in blood pressure, whereas blood pressure was unchanged in mice fed high-K+ diets. Notably, 10 days of K+ depletion induced diabetes insipidus and upregulation of phosphorylated NaCl cotransporter, proximal Na+ transporters, and pendrin, likely contributing to the K+-deficient NaCl sensitivity. While the anionic content with high-K+ diets had distinct effects on transporter expression along the nephron, both K+ basic and KCl diets had a similar increase in blood pressure. The blood pressure elevation on high-K+ diets correlated with increased Na+-K+-2Cl- cotransporter and γ-epithelial Na+ channel expression and increased urinary response to furosemide and amiloride. We conclude that the dietary K+ maneuvers used here did not recapitulate the inverse effects of K+ on blood pressure observed in human epidemiological studies. This may be due to the extreme degree of K+ stress, the low-Na+-to-K+ ratio, the duration of treatment, and the development of other coinciding events, such as diabetes insipidus. These factors must be taken into consideration when studying the physiological effects of dietary K+ loading and depletion.

MATÉRIAUX
Référence du produit
Marque
Description du produit

Sigma-Aldrich
Anti-Na+/HCO3- Cotransporter Antibody, from rabbit, purified by affinity chromatography