What question did this study set out to answer?

This study aims to understand how angiotensin II influences the baroreceptor reflex at the nucleus tractus solitarii in controlling heart rate.

February 1, 1988Hypertension

Baroreceptor reflex modulation by angiotensin II at the nucleus tractus solitarii.

View Full Paper

Ask AI

Bookmark

Why the study?

Does NTS microinjection of [Sar1, Thr8]Ang II alter baroreceptor reflex sensitivity in anesthetized rats?

Population

Anesthetized rats

Comparison

Bilateral microinjection of [Sar1, Thr8]Ang II… vs Vehicle microinjection into the NTS and baseline

Design

Preclinical

Authors

MCMaria José Campagnole‐SantosGeneral Cardiology DDDebra I. DizVascular Medicine CFCarlos M. FerrarioPreventive Cardiology

Discussion

Member takes

Implication

NTS Ang II blockade augments baroreflex sensitivity to pressor stimuli in rats; leaves open relevance to conscious humans or clinical hypertension.

Key Points

This study aims to understand how angiotensin II influences the baroreceptor reflex at the nucleus tractus solitarii in controlling heart rate.
Anesthetized rats received microinjections of the angiotensin II antagonist [Sar1, Thr8]Ang II into the nucleus tractus solitarii.
Reflex changes in heart rate were measured after intravenous injections of phenylephrine or sodium nitroprusside before and after microinjection.
Baroreceptor reflex sensitivity was assessed by the slope of the pulse interval versus mean arterial pressure relationship.
After angiotensin II antagonist injection, baroreceptor reflex sensitivity to increases in pressure significantly improved (slope: 0.60 +/- 0.09 ms/mm Hg) compared to before injection (slope: 0.42 +/- 0.07 ms/mm Hg).
No significant changes were observed in reflex sensitivity to decreases in pressure after antagonist injection, indicating selective effects.
Vehicle injections did not affect baroreceptor reflex sensitivity index.

Structured PICO

Does NTS microinjection of [Sar1, Thr8]Ang II alter baroreceptor reflex sensitivity in anesthetized rats?

Population

Anesthetized rats

Intervention

Bilateral microinjection of [Sar1, Thr8]Ang II (100 pmol) into the nucleus tractus solitarii (NTS)

Comparator

Vehicle microinjection into the NTS and baseline (before injection)

Outcome

Baroreceptor reflex sensitivity (slope of the relationship between the change in pulse interval and the change in mean arterial pressure)surrogate

Inhibition of endogenous Ang II in the NTS facilitates baroreceptor reflex sensitivity to increases in blood pressure in anesthetized rats.

Cite This Study

Campagnole‐Santos et al. (1988) studied this question.

synapsesocial.com/papers/6a727f8322b3175134db76e5 https://doi.org/10.1161/01.hyp.11.2_pt_2.i167

View Full Paper

Ask AI

Bookmark

Implication

NTS Ang II blockade augments baroreflex sensitivity to pressor stimuli in rats; leaves open relevance to conscious humans or clinical hypertension.

Baroreceptor reflex modulation by angiotensin II at the nucleus tractus solitarii.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Baroreceptor reflex modulation by angiotensin II at the nucleus tractus solitarii.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider