What question did this study set out to answer?

To determine how angiotensin interacts with sympathetic baroreceptor reflexes to maintain systemic arterial blood pressure during orthostatic stress.

January 1, 1982Clinical Science

Functional Interaction between Angiotensin and Sympathetic Reflexes in Cats

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Population

Anaesthetized cats

Comparison

Converting-enzyme inhibitor or angiotensin II… vs LBNP alone or CEI administered alone

Design

Preclinical

Follow-up

acute (minutes)

Authors

RHR HattonOrlando Health DCD.P. CloughHannah Research Foundation SAS. A. AdigunUniversity of Lagos

Discussion

Member takes

Implication

Angiotensin may facilitate sympathetic BP maintenance during reflexes; animal data leave open clinical CEI implications.

Key Points

To determine how angiotensin interacts with sympathetic baroreceptor reflexes to maintain systemic arterial blood pressure during orthostatic stress.
Simulated orthostatic stress in anaesthetized cats using lower-body negative pressure (-50 mmHg for 10 min) while monitoring central venous pressure, systemic arterial blood pressure, and plasma renin activity.
Administered a converting-enzyme inhibitor or the angiotensin II antagonist [Sar1,Ala8] ANG II 75 seconds after initiating suction and recorded sympathetic efferent nerve activity.
Lower-body negative pressure induced transient reductions in central venous pressure and systemic arterial blood pressure, with arterial pressure recovering within 30 seconds alongside tachycardia before plasma renin activity increased from baseline (2.9–3.2 ng h⁻¹ ml⁻¹) at approximately 5 minutes.
Administering a converting-enzyme inhibitor or an angiotensin II antagonist during lower-body suction provoked a greater and more sustained reduction in arterial blood pressure than when given alone.
The sustained hypotension provoked by converting-enzyme inhibition occurred without any reduction in sympathetic efferent nerve activity, demonstrating a peripheral neurogenic mechanism.

Structured PICO

Population

Anaesthetized cats

Intervention

Converting-enzyme inhibitor (CEI) or angiotensin II antagonist ([Sar1,Ala8] ANG II) administered during lower-body negative pressure (LBNP)

Comparator

LBNP alone or CEI administered alone

Outcome

Changes in arterial blood pressure, central venous pressure, and sympathetic efferent nerve activitysurrogate

Angiotensin interacts with the sympathetic nervous system to maintain arterial blood pressure during homeostatic reflex activation, and converting-enzyme inhibition reduces the efficiency of these reflexes.

Cite This Study

Hatton et al. (1982) studied this question.

synapsesocial.com/papers/6a70c811a528af2d65c3bb84 https://doi.org/10.1042/cs0620051

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Functional Interaction between Angiotensin and Sympathetic Reflexes in Cats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Functional Interaction between Angiotensin and Sympathetic Reflexes in Cats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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Also Consider