Тип публикации: статья из журнала

Год издания: 1999

Идентификатор DOI: 10.1046/j.1523-1755.1999.00255.x

Ключевые слова: dietary K, growth and development, proximal tubule, vasoconstriction, renal function

Аннотация: Chronic K depletion inhibits renal brush border membrane Na/sulfate cotransport.

<i>Background.</i> The purpose of this study was to determine if dietary potassium (K) deficiency regulates renal proximal tubular sodium gradient-dependent sulfate transport (Na/S_i cotransport) in the rat and, furthermore, determine if the regulation takes place at the level of the recently cloned Na/S_i cotransport system (NaS_i -1).

<i>Methods and Results.</i> Rats treated chronically (seven days) with a K-deficient diet had a significant decrease in serum S_i levels and an increase in fractional excretion of ultrafilterable S_i, which paralleled a significant decrease in brush border membrane (BBM) Na/S_i cotransport activity. The decrease in BBM Na/S_i cotransport activity was associated with decreases in BBM NaS_i -1 protein and renal cortical NaS_i -1 mRNA abundance. In addition, in <i>Xenopus</i> oocytes injected with mRNA from kidney cortex slices of K-deficient rats, there was a significant reduction in the induced Na/S_i cotransport, whereas there was no alteration in l-leucine uptake, suggesting that in K-deficient rats, there is a specific decrease in functional mRNA encoding the NaS_i -1 mRNA.

<i>Conclusion.</i> These findings indicate that chronic K deficiency leads to a reduction in serum S_i levels and an increase fractional excretion of S_i, and reduces S_i reabsorption by down-regulating the expression of the proximal tubular Na/S_i -1 cotransporter protein and mRNA.

Журнал: Kidney International

Выпуск журнала: Т. 55, № 1

Номера страниц: 244-251

ISSN журнала: 00852538

Издатель: John Wiley &amp; Sons

• Markovich Daniel (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Wang Huamin (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Puttaparthi Krishna (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Zajicek Hubert (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Rogers Thomas (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Murer Heini (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Biber Jurg (Department of Physiology and Pharmacology, University of Queensland, Australia)
• Levi Moshe (Department of Physiology and Pharmacology, University of Queensland, Australia)

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