What question did this study set out to answer?

To determine whether increased brain sodium and ouabain-like activity trigger cardiovascular and sympathetic responses via the brain renin-angiotensin system.

January 1, 1996AJP Heart and Circulatory Physiology

Sympathoexcitatory and pressor responses to increased brain sodium and ouabain are mediated via brain ANG II

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Population

Conscious Wistar rats

Comparison

Intracerebroventricular administration of 0.3 M… vs Baseline responses and gamma-globulins

Design

Preclinical

Authors

BHBing‐Shen HuangMemorial Hospital of South Bend FLFrans H. H. LeenenPreventive Cardiology

Discussion

Member takes

Implication

Hypothesis-generating for brain RAS in sodium/ouabain sympathoexcitation in rats; leaves open translation to human hypertension.

Key Points

To determine whether increased brain sodium and ouabain-like activity trigger cardiovascular and sympathetic responses via the brain renin-angiotensin system.
Administered intracerebroventricular hypertonic saline (0.3 M NaCl), ouabain, and angiotensin II to conscious Wistar rats pretreated with an intravenous vasopressin antagonist.
Recorded mean arterial pressure, heart rate, and renal sympathetic nerve activity before and after intracerebroventricular pretreatment with losartan, ouabain-binding Fab fragments, or control gamma-globulins.
Intracerebroventricular losartan completely blocked responses to angiotensin II and 0.3 M NaCl, while reducing ouabain-induced pressor responses by 50% to 70% and heart rate/sympathetic activity increases by 60% to 80%.
Intracerebroventricular Fab fragments blocked the cardiovascular and sympathetic responses to 0.3 M NaCl and ouabain but had no effect on responses to angiotensin II.

Structured PICO

Population

Conscious Wistar rats

Intervention

Intracerebroventricular administration of 0.3 M NaCl, ouabain, and ANG II, with pretreatments including losartan or Fab fragments (Digibind), and intravenous AVP antagonist

Comparator

Baseline responses (before pretreatment) and gamma-globulins (as control for Fab fragments)

Outcome

Changes in mean arterial pressure, heart rate (HR), and renal sympathetic nerve activity (RSNA)surrogate

An acute rise in brain sodium concentration increases brain ouabain-like activity, which exerts sympathoexcitatory and pressor effects partly via activation of the brain renin-angiotensin system.

Cite This Study

Huang et al. (1996) studied this question.

synapsesocial.com/papers/6a81e4d2dc834c04ade1d37e https://doi.org/10.1152/ajpheart.1996.270.1.h275

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Sympathoexcitatory and pressor responses to increased brain sodium and ouabain are mediated via brain ANG II

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Sympathoexcitatory and pressor responses to increased brain sodium and ouabain are mediated via brain ANG II

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider