| Autor: |
Ares GR; Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital , Detroit, Michigan., Kassem KM; Department of Internal Medicine, University of Cincinnati Medical Center , Cincinnati, Ohio., Ortiz PA; Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital , Detroit, Michigan.; Department of Physiology, Wayne State University , Detroit, Michigan. |
| Jazyk: |
angličtina |
| Zdroj: |
American journal of physiology. Renal physiology [Am J Physiol Renal Physiol] 2019 Mar 01; Vol. 316 (3), pp. F550-F557. Date of Electronic Publication: 2018 Dec 05. |
| DOI: |
10.1152/ajprenal.00136.2018 |
| Abstrakt: |
The thick ascending limb (TAL) reabsorbs 25% of the filtered NaCl through the Na + -K + -2Cl - cotransporter (NKCC2). NKCC2 activity is directly related to surface NKCC2 expression and phosphorylation. Higher NaCl reabsorption by TALs is linked to salt-sensitive hypertension, which is linked to consumption of fructose in the diet. However, little is known about the effects of fructose on renal NaCl reabsorption. We hypothesized that fructose, but not glucose, acutely enhances TAL-dependent NaCl reabsorption by increasing NKCC2 activity via stimulation of surface NKCC2 levels and phosphorylation at Thr 96/101 . We found that fructose (5 mM) increased transport-related O 2 consumption in TALs by 11.1 ± 3.2% ( P < 0.05). The effect of fructose on O 2 consumption was blocked by furosemide. To study the effect of fructose on NKCC2 activity, we measured the initial rate of NKCC2-dependent thallium influx. We found that 20 min of treatment with fructose (5 mM) increased NKCC2 activity by 58.5 ± 16.9% ( P < 0.05). We then used surface biotinylation to measure surface NKCC2 levels in rat TALs. Fructose increased surface NKCC2 expression in a concentration-dependent manner (22 ± 5, 49 ± 10, and 101 ± 59% of baseline with 1, 5, and 10 mM fructose, respectively, P < 0.05), whereas glucose or a glucose metabolite did not. Fructose did not change NKCC2 phosphorylation at Thre 96/101 or total NKCC2 expression. We concluded that acute fructose treatment increases NKCC2 activity by enhancing surface NKCC2 expression, rather than NKCC2 phosphorylation. Our data suggest that fructose consumption could contribute to salt-sensitive hypertension by stimulating NKCC2-dependent NaCl reabsorption in TALs. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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