What question did this study set out to answer?

This study aims to determine the heterogeneous vascular responses to cold pressor stimulation and the role of adrenergic receptor function.

January 1, 2000HypertensionOpen Access

Dissociation Between Neural and Vascular Responses to Sympathetic Stimulation

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Why the study?

Does sympathetic stimulation alter regional vascular resistance and norepinephrine spillover in healthy subjects?

Population

8 healthy subjects

Comparison

Sympathetic stimulation induced by baroreflex… vs Baseline measurements

Design

Other

Authors

GJGiris JacobGeneral Cardiology FCFernando CostaAmerican Heart Association JSJ. R. ShannonSeton Hall University

Discussion

Member takes

Implication

Limb-specific vascular responses during sympathetic activation may influence regional hemodynamics; leaves open relevance to orthostatic or hypertensive states.

Key Points

This study aims to determine the heterogeneous vascular responses to cold pressor stimulation and the role of adrenergic receptor function.
Measured local norepinephrine spillover and blood flow in arms and legs at baseline and during sympathetic stimulation.
Used baroreflex mechanisms with nitroprusside infusion and cold pressor stimulation in 8 healthy subjects.
Infused increasing doses of isoproterenol and phenylephrine to estimate beta-mediated vasodilation and alpha-induced vasoconstriction.
At baseline, legs showed higher vascular resistance (27±5 U) compared to arms (17±2 U, P=0.05).
During cold stimulation, vascular resistance increased in arms (20±9%) but decreased in legs (-7±4%, P=0.03).
Beta-mediated vasodilation was significantly lower in legs compared to arms.

Structured PICO

Does sympathetic stimulation alter regional vascular resistance and norepinephrine spillover in healthy subjects?

Population

8 healthy subjects

Intervention

Sympathetic stimulation induced by baroreflex mechanisms (nitroprusside infusion) or cold pressor stimulation, and intra-arterial infusion of isoproterenol and phenylephrine

Comparator

Baseline measurements

Outcome

Local norepinephrine spillover and blood flow/vascular resistance in arms and legssurrogate

There is a dissociation between sympathetic neural activation and vascular resistance responses to cold stress in the lower limbs of healthy subjects, which cannot be explained by differences in adrenergic receptor responses.

Cite This Study

Jacob et al. (2000) studied this question.

synapsesocial.com/papers/6a70464bac440176ef28ed0c https://doi.org/10.1161/01.hyp.35.1.76

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Implication

Limb-specific vascular responses during sympathetic activation may influence regional hemodynamics; leaves open relevance to orthostatic or hypertensive states.

Dissociation Between Neural and Vascular Responses to Sympathetic Stimulation

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Dissociation Between Neural and Vascular Responses to Sympathetic Stimulation

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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