TY - JOUR
T1 - Dietary salt modifies the blood pressure response to renin-angiotensin inhibition in experimental chronic kidney disease
AU - Bovee, Dominique M.
AU - Uijl, Estrellita
AU - Severs, David
AU - Rubio-Beltran, Eloisa
AU - van Veghel, Richard
AU - van den Brink, Antoinette Maassen
AU - Joles, Jaap A.
AU - Zietse, Robert
AU - Cuevas, Catherina A.
AU - Danser, A. H. Jan
AU - Hoorn, Ewout J.
N1 - Funding Information:
This study is supported by Dutch Kidney Foundation Grant 14OK19 (to D.M.B. and E.J.H.).
Publisher Copyright:
© 2021 American Physiological Society. All rights reserved.
PY - 2021/4/8
Y1 - 2021/4/8
N2 - Chronic kidney disease contributes to hypertension, but the mechanisms are incompletely understood. To address this, we applied the 5/6th nephrectomy rat model to characterize hypertension and the response to dietary salt and renin-Angiotensin inhibition. 5/6th nephrectomy caused low-renin, salt-sensitive hypertension with hyperkalemia and unsuppressed aldosterone. Compared with sham rats, 5/6th nephrectomized rats had lower Na/H exchanger isoform 3, Na-K-2Cl cotransporter, Na-Cl cotransporter, a-epithelial Na channel (ENaC), and Kir4.1 levels but higher serum and glucocorticoid-regulated kinase 1, prostasin, c-ENaC, and Kir5.1 levels. These differences correlated with plasma renin, aldosterone, and/or K. On a normal-salt diet, adrenalectomy (0 ± 9 mmHg) and spironolactone (11 ± 10 mmHg) prevented a progressive rise in blood pressure (10 ± 8 mmHg), and this was enhanced in combination with losartan (41 ± 12 and 43 ± 9 mmHg). A high-salt diet caused skin Na and water accumulation and aggravated hypertension that could only be attenuated by spironolactone (16 ± 7 mmHg) and in which the additive effect of losartan was lost. Spironolactone also increased natriuresis, reduced skin water accumulation, and restored vasorelaxation. In summary, in the 5/6th nephrectomy rat chronic kidney disease model, salt-sensitive hypertension develops with a selective increase in c-ENaC and despite appropriate transporter adaptations to low renin and hyperkalemia. With a normal-salt diet, hypertension in 5/6th nephrectomy depends on angiotensin II and aldosterone, whereas a high-salt diet causes more severe hypertension mediated through the mineralocorticoid receptor. NEW and NOTEWORTHY Chronic kidney disease (CKD) causes salt-sensitive hypertension, but the interactions between dietary salt and the renin-Angiotensin system are incompletely understood. In rats with CKD on a normal-salt diet targeting aldosterone, the mineralocorticoid receptor (MR) and especially angiotensin II reduced blood pressure. On a high-salt diet, however, only MR blockade attenuated hypertension. These results reiterate the importance of dietary salt restriction to maintain renin-Angiotensin system inhibitor efficacy and specify the MR as a target in CKD.
AB - Chronic kidney disease contributes to hypertension, but the mechanisms are incompletely understood. To address this, we applied the 5/6th nephrectomy rat model to characterize hypertension and the response to dietary salt and renin-Angiotensin inhibition. 5/6th nephrectomy caused low-renin, salt-sensitive hypertension with hyperkalemia and unsuppressed aldosterone. Compared with sham rats, 5/6th nephrectomized rats had lower Na/H exchanger isoform 3, Na-K-2Cl cotransporter, Na-Cl cotransporter, a-epithelial Na channel (ENaC), and Kir4.1 levels but higher serum and glucocorticoid-regulated kinase 1, prostasin, c-ENaC, and Kir5.1 levels. These differences correlated with plasma renin, aldosterone, and/or K. On a normal-salt diet, adrenalectomy (0 ± 9 mmHg) and spironolactone (11 ± 10 mmHg) prevented a progressive rise in blood pressure (10 ± 8 mmHg), and this was enhanced in combination with losartan (41 ± 12 and 43 ± 9 mmHg). A high-salt diet caused skin Na and water accumulation and aggravated hypertension that could only be attenuated by spironolactone (16 ± 7 mmHg) and in which the additive effect of losartan was lost. Spironolactone also increased natriuresis, reduced skin water accumulation, and restored vasorelaxation. In summary, in the 5/6th nephrectomy rat chronic kidney disease model, salt-sensitive hypertension develops with a selective increase in c-ENaC and despite appropriate transporter adaptations to low renin and hyperkalemia. With a normal-salt diet, hypertension in 5/6th nephrectomy depends on angiotensin II and aldosterone, whereas a high-salt diet causes more severe hypertension mediated through the mineralocorticoid receptor. NEW and NOTEWORTHY Chronic kidney disease (CKD) causes salt-sensitive hypertension, but the interactions between dietary salt and the renin-Angiotensin system are incompletely understood. In rats with CKD on a normal-salt diet targeting aldosterone, the mineralocorticoid receptor (MR) and especially angiotensin II reduced blood pressure. On a high-salt diet, however, only MR blockade attenuated hypertension. These results reiterate the importance of dietary salt restriction to maintain renin-Angiotensin system inhibitor efficacy and specify the MR as a target in CKD.
UR - http://www.scopus.com/inward/record.url?scp=85104159951&partnerID=8YFLogxK
U2 - 10.1152/ajprenal.00603.2020
DO - 10.1152/ajprenal.00603.2020
M3 - Article
C2 - 33586496
SN - 1931-857X
VL - 320
SP - F654-F668
JO - American Journal of Physiology-Renal Physiology
JF - American Journal of Physiology-Renal Physiology
IS - 4
ER -