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Published on: February 10, 2013
Plasma catecholamine responses to exercise after training with beta-adrenergic blockade
E E Wolfel1, W R Hiatt, H L Brammell
1Department of Medicine, University of Colorado Health Sciences Center, Denver 80262.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|February 1, 1990
Summary
Beta-adrenergic blockade affects how the body adapts to exercise training. Exercise training typically lowers norepinephrine (NE) and epinephrine (EPI), but these changes were blunted by beta-blockers.
Area of Science:
- Exercise Physiology
- Cardiovascular Pharmacology
Background:
- Exercise training reduces sympathetic nervous system activity, indicated by lower plasma norepinephrine (NE) and epinephrine (EPI).
- The impact of beta-adrenergic blockade on these exercise-induced adaptations is not fully understood.
Purpose of the Study:
- To investigate how beta-adrenergic blockade influences the changes in plasma catecholamine levels (NE and EPI) following exercise conditioning.
- To determine if beta-blockers alter the sympathetic nervous system's adaptation to a 6-week exercise program.
Main Methods:
- 24 healthy males underwent a 6-week exercise training program.
- Subjects were randomized to placebo, atenolol, or nadolol groups.
- Plasma NE and EPI levels were measured at rest and during submaximal and maximal exercise before and after training, with and without medication.
Main Results:
- Resting NE and EPI levels did not change post-training in any group.
- During submaximal exercise, NE decreased with placebo and atenolol but not nadolol; EPI decreased only with placebo.
- Maximal exercise showed increased NE in all groups post-training; EPI increased with nadolol but not placebo or atenolol.
- Training-induced catecholamine changes were masked or blunted by beta-blockade.
Conclusions:
- Beta-adrenergic blockade significantly impacts the sympathetic nervous system's adaptations to exercise training.
- These effects are particularly noticeable during submaximal exercise, where training-induced reductions in catecholamines are blunted by beta-blockers.
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