The exaggerated natriuresis of essential hypertension occurs independently of changes in renal medullary blood flow

Kasper B. Assersen, Poul F. Høilund-Carlsen, Michael H. Olsen, Sara V. Greve, Jens C. Gam-Hadberg, Poul Erik Braad, Mads Damkjaer, Peter Bie*

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Resumé

Aims: In patients with essential hypertension, abnormal renal sodium handling includes exaggerated natriuresis in response to extracellular volume expansion. We tested the hypothesis that exaggerated natriuresis is associated with increases in medullary and/or cortical renal blood flow. Methods: Patients with mild essential hypertension, but no signs of end organ damage, and control subjects were studied after 4 days of dietary standardization (<60 mmol Na +  day −1 ) preceded in patients by a 14-day drug washout period. On the study day, subjects received a 4-hour intravenous volume expansion with saline (2.1% of body mass). Renal medullary and cortical blood flows were measured by PET scanning using H 2 15 O as tracer; anatomical regions of interest were defined by contrast-enhanced CT scanning. Results: In patients, arterial blood pressure increased during volume expansion (107 ± 2-114 ± 3 mm Hg, P < 0.05) in contrast to the control group (92 ± 2-92 ± 2 mm Hg). Renal sodium excretion increased more in patients than in controls (+133 ± 31 µmol min −1 vs +61 ± 14 µmol min −1 , respectively, P < 0.05) confirming exaggerated natriuresis. During volume expansion, renal medullary blood flow did not change significantly in patients (2.8 ± 0.4-2.5 ± 0.5 mL (g tissue) −1  min −1 ) or in controls (3.2 ± 0.3-3.1 ± 0.2 mL (g tissue) −1 min −1 ). In control subjects, renal cortical blood flow fell during volume expansion (4.1 ± 0.3-3.7 ± 0.2 mL (g tissue) −1  min −1 , P < 0.05) in contrast to patients in which deviations remained insignificant. Conclusion: Exaggerated natriuresis, a hallmark of essential hypertension, is not mediated by increases in regional, renal blood flow.

OriginalsprogEngelsk
Artikelnummere13266
TidsskriftActa Physiologica
Vol/bind226
Udgave nummer3
Antal sider10
ISSN1748-1708
DOI
StatusUdgivet - 1. jul. 2019

Fingeraftryk

Natriuresis
Kidney
Regional Blood Flow
Essential Hypertension
Arterial Pressure
Control Groups
Pharmaceutical Preparations

Citer dette

@article{755f8f366d8d4a74a9ac489f158a952d,
title = "The exaggerated natriuresis of essential hypertension occurs independently of changes in renal medullary blood flow",
abstract = "Aims: In patients with essential hypertension, abnormal renal sodium handling includes exaggerated natriuresis in response to extracellular volume expansion. We tested the hypothesis that exaggerated natriuresis is associated with increases in medullary and/or cortical renal blood flow. Methods: Patients with mild essential hypertension, but no signs of end organ damage, and control subjects were studied after 4 days of dietary standardization (<60 mmol Na +  day −1 ) preceded in patients by a 14-day drug washout period. On the study day, subjects received a 4-hour intravenous volume expansion with saline (2.1{\%} of body mass). Renal medullary and cortical blood flows were measured by PET scanning using H 2 15 O as tracer; anatomical regions of interest were defined by contrast-enhanced CT scanning. Results: In patients, arterial blood pressure increased during volume expansion (107 ± 2-114 ± 3 mm Hg, P < 0.05) in contrast to the control group (92 ± 2-92 ± 2 mm Hg). Renal sodium excretion increased more in patients than in controls (+133 ± 31 µmol min −1 vs +61 ± 14 µmol min −1 , respectively, P < 0.05) confirming exaggerated natriuresis. During volume expansion, renal medullary blood flow did not change significantly in patients (2.8 ± 0.4-2.5 ± 0.5 mL (g tissue) −1  min −1 ) or in controls (3.2 ± 0.3-3.1 ± 0.2 mL (g tissue) −1 min −1 ). In control subjects, renal cortical blood flow fell during volume expansion (4.1 ± 0.3-3.7 ± 0.2 mL (g tissue) −1  min −1 , P < 0.05) in contrast to patients in which deviations remained insignificant. Conclusion: Exaggerated natriuresis, a hallmark of essential hypertension, is not mediated by increases in regional, renal blood flow.",
keywords = "hypertension, low salt diet, renal blood flow, renal haemodynamics, sodium sensitivity, volume expansion",
author = "Assersen, {Kasper B.} and H{\o}ilund-Carlsen, {Poul F.} and Olsen, {Michael H.} and Greve, {Sara V.} and Gam-Hadberg, {Jens C.} and Braad, {Poul Erik} and Mads Damkjaer and Peter Bie",
year = "2019",
month = "7",
day = "1",
doi = "10.1111/apha.13266",
language = "English",
volume = "226",
journal = "Acta Physiologica (Print)",
issn = "1748-1708",
publisher = "Wiley-Blackwell",
number = "3",

}

The exaggerated natriuresis of essential hypertension occurs independently of changes in renal medullary blood flow. / Assersen, Kasper B.; Høilund-Carlsen, Poul F.; Olsen, Michael H.; Greve, Sara V.; Gam-Hadberg, Jens C.; Braad, Poul Erik; Damkjaer, Mads; Bie, Peter.

I: Acta Physiologica, Bind 226, Nr. 3, e13266, 01.07.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - The exaggerated natriuresis of essential hypertension occurs independently of changes in renal medullary blood flow

AU - Assersen, Kasper B.

AU - Høilund-Carlsen, Poul F.

AU - Olsen, Michael H.

AU - Greve, Sara V.

AU - Gam-Hadberg, Jens C.

AU - Braad, Poul Erik

AU - Damkjaer, Mads

AU - Bie, Peter

PY - 2019/7/1

Y1 - 2019/7/1

N2 - Aims: In patients with essential hypertension, abnormal renal sodium handling includes exaggerated natriuresis in response to extracellular volume expansion. We tested the hypothesis that exaggerated natriuresis is associated with increases in medullary and/or cortical renal blood flow. Methods: Patients with mild essential hypertension, but no signs of end organ damage, and control subjects were studied after 4 days of dietary standardization (<60 mmol Na +  day −1 ) preceded in patients by a 14-day drug washout period. On the study day, subjects received a 4-hour intravenous volume expansion with saline (2.1% of body mass). Renal medullary and cortical blood flows were measured by PET scanning using H 2 15 O as tracer; anatomical regions of interest were defined by contrast-enhanced CT scanning. Results: In patients, arterial blood pressure increased during volume expansion (107 ± 2-114 ± 3 mm Hg, P < 0.05) in contrast to the control group (92 ± 2-92 ± 2 mm Hg). Renal sodium excretion increased more in patients than in controls (+133 ± 31 µmol min −1 vs +61 ± 14 µmol min −1 , respectively, P < 0.05) confirming exaggerated natriuresis. During volume expansion, renal medullary blood flow did not change significantly in patients (2.8 ± 0.4-2.5 ± 0.5 mL (g tissue) −1  min −1 ) or in controls (3.2 ± 0.3-3.1 ± 0.2 mL (g tissue) −1 min −1 ). In control subjects, renal cortical blood flow fell during volume expansion (4.1 ± 0.3-3.7 ± 0.2 mL (g tissue) −1  min −1 , P < 0.05) in contrast to patients in which deviations remained insignificant. Conclusion: Exaggerated natriuresis, a hallmark of essential hypertension, is not mediated by increases in regional, renal blood flow.

AB - Aims: In patients with essential hypertension, abnormal renal sodium handling includes exaggerated natriuresis in response to extracellular volume expansion. We tested the hypothesis that exaggerated natriuresis is associated with increases in medullary and/or cortical renal blood flow. Methods: Patients with mild essential hypertension, but no signs of end organ damage, and control subjects were studied after 4 days of dietary standardization (<60 mmol Na +  day −1 ) preceded in patients by a 14-day drug washout period. On the study day, subjects received a 4-hour intravenous volume expansion with saline (2.1% of body mass). Renal medullary and cortical blood flows were measured by PET scanning using H 2 15 O as tracer; anatomical regions of interest were defined by contrast-enhanced CT scanning. Results: In patients, arterial blood pressure increased during volume expansion (107 ± 2-114 ± 3 mm Hg, P < 0.05) in contrast to the control group (92 ± 2-92 ± 2 mm Hg). Renal sodium excretion increased more in patients than in controls (+133 ± 31 µmol min −1 vs +61 ± 14 µmol min −1 , respectively, P < 0.05) confirming exaggerated natriuresis. During volume expansion, renal medullary blood flow did not change significantly in patients (2.8 ± 0.4-2.5 ± 0.5 mL (g tissue) −1  min −1 ) or in controls (3.2 ± 0.3-3.1 ± 0.2 mL (g tissue) −1 min −1 ). In control subjects, renal cortical blood flow fell during volume expansion (4.1 ± 0.3-3.7 ± 0.2 mL (g tissue) −1  min −1 , P < 0.05) in contrast to patients in which deviations remained insignificant. Conclusion: Exaggerated natriuresis, a hallmark of essential hypertension, is not mediated by increases in regional, renal blood flow.

KW - hypertension

KW - low salt diet

KW - renal blood flow

KW - renal haemodynamics

KW - sodium sensitivity

KW - volume expansion

U2 - 10.1111/apha.13266

DO - 10.1111/apha.13266

M3 - Journal article

C2 - 30770642

AN - SCOPUS:85062984112

VL - 226

JO - Acta Physiologica (Print)

JF - Acta Physiologica (Print)

SN - 1748-1708

IS - 3

M1 - e13266

ER -