Endogenous opioids may modulate catecholamine secretion during high intensity exercise

Autor: Sergio G. DaSilva, Cathy Weikart, Theodore J. Angelopoulos, Robert J. Robertson, Bart G. Denys, Timothy J. Michael
Rok vydání: 1995
Předmět:
Zdroj: European Journal of Applied Physiology and Occupational Physiology. 70:195-199
ISSN: 1439-6327
0301-5548
DOI: 10.1007/bf00238563
Popis: To determine the effect of endogenous opioids on catecholamine response during intense exercise [80% maximal oxygen uptake ( $$\dot V$$ O2max)], nine fit men [mean (SE) ( $$\dot V$$ O2max, 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.
Databáze: OpenAIRE
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