Endogenous opioids may modulate catecholamine secretion during high intensity exercise.
Eur J Appl Physiol Occup Physiol
; 70(3): 195-9, 1995.
Article
in En
| MEDLINE
| ID: mdl-7607192
ABSTRACT
To determine the effect of endogenous opioids on catecholamine response during intense exercise [80% maximal oxygen uptake (VO2max)], nine fit men [mean (SE) VO2max, 63.9 (1.7) ml.kg-1.min-1; age 27.6 (1.6) years] were studied during two treadmill exercise trials. A double-blind experimental design was used with subjects undertaking the two exercise trials in counterbalanced order. Exercise trials were 20 min in duration and were conducted 7 days apart. One exercise trial was undertaken following administration of naloxone (N; 1.2 mmol.l-1; 3 ml) and the other after receiving a placebo (P; 0.9% saline; 3 ml). Prior to each experimental trial a flexible catheter was placed into an antecubital vein and baseline blood samples were collected. Immediately afterwards, each subject received bolus injection of either N or P. Blood samples were also collected after 20 min of continuous exercise while running. Epinephrine and norepinephrine were higher (P < 0.05) in the N than P exercise trial with mean (SE) values of 1679 (196) versus 1196 (155) pmol.l-1 and 24 (2.2) versus 20 (1.7) nmol.l-1, respectively. Glucose and lactate were higher (P < 0.05) in the N than P exercise trial with values of 7 (0.37) versus 5.9 (0.31) mmol.l-1 and 6.9 (1.1) versus 5.3 (0.9) mmol.l-1 respectively. These data suggest an opioid inhibition in the release of catecholamines during intense exercise.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Exercise
/
Epinephrine
/
Norepinephrine
/
Opioid Peptides
Type of study:
Clinical_trials
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Eur J Appl Physiol Occup Physiol
Year:
1995
Document type:
Article