August 1, 1988Journal of Applied Physiology
Plasma norepinephrine and muscle sympathetic discharge during rhythmic exercise in humans
Population
6 healthy men, ages 20-30 years
Comparison
2-min bouts of two-arm cycling exercise at… vs Rest (control period before exercise)
Design
Other
Authors
Discussion
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Implication
Norepinephrine may proxy MSNA during graded exercise in healthy adults; leaves open validation in cardiovascular disease.
Key Points
- This research aims to explore how plasma norepinephrine levels relate to muscle sympathetic nerve activity during exercise.
- Six healthy men aged 20-30 performed two minutes of cycling exercise at various power outputs
- Muscle sympathetic nerve activity was measured continuously via intraneural recordings
- Venous blood samples were analyzed for plasma norepinephrine concentrations by high-performance liquid chromatography.
- Muscle sympathetic nerve activity and norepinephrine significantly increased only at 40W, 60W, and 80W exercises (P<0.05).
- No increases in MSNA or norepinephrine were observed at 0W, 10W, and 20W power outputs; changes were minimal (0-16 +/- 1%).
- There was a strong positive correlation between MSNA and PNE responses across the power levels (r=0.80, P<0.001).
Structured PICO
P
Population
6 healthy men, ages 20-30 years
I
Intervention
2-min bouts of two-arm cycling exercise at graded power outputs (0, 10, 20, 40, 60, and 80 W)
C
Comparator
Rest (control period before exercise)
O
Outcome
Relationship between plasma norepinephrine concentrations (PNE) and efferent muscle sympathetic nerve activity (MSNA)surrogate
Plasma norepinephrine and muscle sympathetic nerve activity increase proportionally during graded rhythmic exercise above a certain threshold.
Cite This Study
Seals et al. (1988) studied this question.