What question did this study set out to answer?

Determine whether vasopressin modulates the baroreflex control of heart rate by altering reflex gain or resetting the set point, and identify the specific receptor subtype mediating this response.

September 1, 1993AJP Regulatory Integrative and Comparative Physiology

Role of V1 receptors in the action of vasopressin on the baroreflex control of heart rate

View Full Paper

Ask AI

Bookmark

Population

Conscious, chronically prepared rabbits

Comparison

Intravenous infusions of vasopressin, selective… vs Baseline/control conditions prior to infusion

Design

Preclinical

Authors

JLJames Ka-Hay LukPrincess Margaret Hospital IAIkem AjaeloHighland Hospital VWVictoria W. Y. WongChinese University of Hong Kong

Discussion

Member takes

Implication

Supports V1-mediated baroreflex resetting in animals; leaves open translation to human autonomic regulation.

Key Points

Determine whether vasopressin modulates the baroreflex control of heart rate by altering reflex gain or resetting the set point, and identify the specific receptor subtype mediating this response.
Assessed conscious, chronically prepared rabbits infused with arginine vasopressin, selective V1 and V2 agonists, oxytocin, or a selective V1 receptor antagonist.
Constructed baroreflex curves using intravenous phenylephrine and nitroprusside infusions and evaluated parameters using a four-parameter logistic model.
Vasopressin infusion (5 ng/kg/min) increased mean arterial pressure by 9 mmHg, reduced heart rate by 31 beats/min, and lowered the baroreflex midpoint (BP50) from 75.9 ± 4.8 to 57.6 ± 1.7 mmHg (P < 0.01) without altering reflex gain.
Pretreatment with the selective V1 receptor antagonist d(CH2)5[Tyr(Me)2]AVP completely abolished vasopressin-induced changes in blood pressure, heart rate, and BP50.
Selective V1 agonist [Phe2,Ile3,Orn8]AVP mimicked the cardiovascular actions of vasopressin and significantly decreased baroreflex BP50 from 73.0 ± 2.2 to 63.8 ± 2.2 mmHg (P < 0.05).

Structured PICO

Population

Conscious, chronically prepared rabbits

Intervention

Intravenous infusions of vasopressin (5 ng.kg-1.min-1), selective vasopressin V1 and V2 receptor agonists, oxytocin, and a vasopressin V1 receptor antagonist (d(CH2)5[Tyr(Me)2]AVP)

Comparator

Baseline/control conditions prior to infusion

Outcome

Baroreflex control of heart rate (BP50 and gain)surrogate

Vasopressin resets the baroreflex control of heart rate to a lower blood pressure via V1 receptors without significantly changing the gain.

Cite This Study

Luk et al. (1993) studied this question.

synapsesocial.com/papers/6a7551d0756843cacbb1f50b https://doi.org/10.1152/ajpregu.1993.265.3.r524

View Full Paper

Ask AI

Bookmark

Role of V1 receptors in the action of vasopressin on the baroreflex control of heart rate

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Role of V1 receptors in the action of vasopressin on the baroreflex control of heart rate

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider