What question did this study set out to answer?

To determine whether brain oxidative stress mediates central sympathetic activation and arterial pressure elevation in salt-sensitive hypertension.

June 19, 2007Hypertension

Sympathoexcitation by Oxidative Stress in the Brain Mediates Arterial Pressure Elevation in Salt-Sensitive Hypertension

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To determine whether brain oxidative stress mediates central sympathetic activation and arterial pressure elevation in salt-sensitive hypertension.
Five- to 6-week-old male Dahl salt-sensitive (DS) and salt-resistant (DR) rats received normal (0.3%) or high-salt (8%) diets for 4 weeks.
Arterial pressure, renal sympathetic nerve activity, and heart rate were recorded in urethane-anesthetized rats after intracerebroventricular infusion of tempol or diphenyleneiodonium.
Hypothalamic NADPH oxidase subunit mRNA expression (p22phox, p47phox, gp91phox) and superoxide production were measured.
Salt loading significantly amplified tempol-induced reductions in DS rats compared to controls for arterial pressure (-29.1±4.8% vs -10.6±3.3%, P<0.01), sympathetic nerve activity (-18.7±2.0% vs -7.1±1.8%, P<0.01), and heart rate (-10.7±2.8% vs -2.0±0.7%, P<0.05).
Central injection of the NADPH oxidase inhibitor diphenyleneiodonium similarly caused significantly greater reductions in pressure, sympathetic activity, and heart rate in salt-loaded DS rats.
High-salt intake increased hypothalamic NADPH-dependent superoxide production and upregulated p22phox, p47phox, and gp91phox mRNA in DS rats but not DR rats.

Structured PICO

Population

5- to 6-week-old male Dahl salt-sensitive rats and salt-resistant rats fed with a normal (0.3%) or high- (8%) salt diet for 4 weeks

Intervention

Intracerebroventricular infusion of tempol (20 or 40 micromol) or diphenyleneiodonium

Comparator

Salt-resistant rats and/or rats without salt loading

Outcome

Changes in arterial pressure, renal sympathetic nerve activity, and heart ratesurrogate

Increased oxidative stress in the brain via NADPH oxidase activation mediates arterial pressure elevation through central sympathoexcitation in salt-sensitive hypertension.

Authors

MFMegumi FujitaYamagata University KAKatsuyuki AndoSeiwa Hospital ANAi NagaeThe University of Tokyo

Discussion

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Implication

Central oxidative stress may mediate salt-sensitive hypertension in rats; extends mechanistic insights but leaves human translation open.

Cite This Study

Fujita et al. (2007) studied this question.

synapsesocial.com/papers/6a819d110dbb8263c158bfb5 https://doi.org/10.1161/hypertensionaha.107.091009

Topics

Hypertension management

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Sympathoexcitation by Oxidative Stress in the Brain Mediates Arterial Pressure Elevation in Salt-Sensitive Hypertension

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Topics

Sympathoexcitation by Oxidative Stress in the Brain Mediates Arterial Pressure Elevation in Salt-Sensitive Hypertension

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Topics

Also Consider