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High‐salt diet induces outward remodelling of efferent arterioles in mice with reduced renal mass
Author(s) -
Zhao L.,
Gao Y.,
Cao X.,
Gao D.,
Zhou S.,
Zhang S.,
Cai X.,
Han F.,
Wilcox C. S.,
Li L.,
Lai E. Y.
Publication year - 2017
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/apha.12759
Subject(s) - efferent , medicine , chemistry , renal mass , endocrinology , anatomy , kidney , afferent , nephrectomy
Aim The glomerular filtration rate ( GFR ) falls progressively in chronic kidney disease ( CKD ) which is caused by a reduction in the number of functional nephrons. The dysfunctional nephron exhibits a lower glomerular capillary pressure that is induced by an unbalance between afferent and efferent arteriole. Therefore, we tested the hypothesis that oxidative stress induced by CKD differentially impairs the structure or function of efferent vs. afferent arterioles. Methods C57 BL /6 mice received sham operations (sham) or 5/6 nephrectomy ( RRM ) and three months of normal‐ or high‐salt diet or tempol. GFR was assessed from the plasma inulin clearance, arteriolar remodelling from media/lumen area ratio, myogenic responses from changes in luminal diameter with increases in perfusion pressure and passive wall compliance from the wall stress/strain relationships. Results Mice with RRM fed a high salt (vs. sham) had a lower GFR (553 ± 25 vs. 758 ± 36 μ L min −1 g −1 kidney, P < 0.01) and a larger efferent arteriolar diameter (9.6 ± 0.8 vs. 7.4 ± 0.7 μ m, P < 0.05) resulting in a lower media/lumen area ratio (1.4 ± 0.1 vs. 2.4 ± 0.2, P < 0.01). These alterations were corrected by tempol. The myogenic responses of efferent arterioles were about one‐half that of afferent arterioles and were unaffected by RRM or salt. Passive wall compliance was reduced by high salt in both afferent and efferent arterioles. Conclusion A reduction in renal mass with a high‐salt diet induces oxidative stress that leads to an outward eutrophic remodelling in efferent arterioles and reduced wall compliance in both afferent and efferent arterioles. This may contribute to the lower GFR in this model of CKD .