What question did this study set out to answer?

To evaluate pressor responses to norepinephrine across acute and chronic stages of renal artery stenosis and investigate the regulatory role of angiotensin II.

September 1, 1978Circulation ResearchOpen Access

Pressor responses to norepinephrine in rabbits with 3-day and 30-day renal artery stenosis. The role of angiotensin II.

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Why the study?

Does angiotensin II mediate the increased pressor response to norepinephrine in rabbits with renal artery stenosis?

Population

Normal rabbits, rabbits with renal artery stenosis of over 30 days' duration, and rabbits with renal artery…

Comparison

Infusions of norepinephrine, angiotensin II, and… vs Responses in normal rabbits and responses…

Design

Preclinical

Authors

SIShûichi IchikawaToyohashi University of Technology JJJ. A. JohnsonAnglia Ruskin University WFW. L. FowlerEast Tennessee State University

Discussion

Member takes

Implication

Should not alter clinical practice; leaves open mechanistic role of angiotensin II in human renovascular hypertension.

Key Points

To evaluate pressor responses to norepinephrine across acute and chronic stages of renal artery stenosis and investigate the regulatory role of angiotensin II.
Assessed pressor responses to norepinephrine infusions in normal control rabbits, prehypertensive rabbits with 3-day renal artery stenosis, and chronic hypertensive rabbits with >30-day stenosis.
Measured baseline plasma renin activity and tested norepinephrine responsiveness during concurrent infusions of subpressor and pressor doses of angiotensin II.
Administered the angiotensin II antagonist [1-sarcosine, 8-isoleucine]angiotensin II to evaluate its capacity to reverse norepinephrine hyperresponsiveness.
Norepinephrine pressor responses were heightened approximately 2.5-fold above normal controls in both 3-day prehypertensive clipped rabbits and chronic hypertensive rabbits.
Plasma renin activity remained normal in 3-day clipped rabbits but fell significantly below normal in chronic hypertensive rabbits.
Angiotensin II antagonism completely abolished norepinephrine hyperresponsiveness in 3-day clipped rabbits and greatly reduced it in chronic hypertensive rabbits without altering baseline arterial pressure.

Structured PICO

Does angiotensin II mediate the increased pressor response to norepinephrine in rabbits with renal artery stenosis?

Population

Normal rabbits, rabbits with renal artery stenosis of over 30 days' duration (chronic renal hypertensive rabbits), and rabbits with renal artery stenosis of 3 days' duration (3-day clipped rabbits)

Intervention

Infusions of norepinephrine, angiotensin II, and angiotensin II antagonist ([1-sarcosine, 8-isoleucine]angiotensin II)

Comparator

Responses in normal rabbits and responses without angiotensin II/antagonist

Outcome

Pressor responses to norepinephrinesurrogate

Angiotensin II plays a crucial role in mediating the increased pressor response to norepinephrine in both prehypertensive and hypertensive phases of renal artery stenosis in rabbits.

Cite This Study

Ichikawa et al. (1978) studied this question.

synapsesocial.com/papers/6a6f9be835aa2c282ce0f39b https://doi.org/10.1161/01.res.43.3.437

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Pressor responses to norepinephrine in rabbits with 3-day and 30-day renal artery stenosis. The role of angiotensin II.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Pressor responses to norepinephrine in rabbits with 3-day and 30-day renal artery stenosis. The role of angiotensin II.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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