Journal of Applied Physiology, Vol 69, Issue 2 604-608, Copyright © 1990 by American Physiological Society
Plasma catecholamines in the aorta and the phrenicoabdominal vein in exercising dogs
L. Beliveau, F. Peronnet, F. Trudeau, G. Brisson and R. Nadeau
Departement d'Education Physique, Universite de Montreal, Quebec, Canada.
Plasma epinephrine and norepinephrine concentrations were measured in the
aorta and phrenicoabdominal vein in five dogs at rest and during
short-duration mild- and moderate-intensity exercise and during prolonged
mild-intensity exercise. Plasma epinephrine and norepinephrine
concentrations increased with exercise in both the aorta and the
phrenicoabdominal vein. Plasma epinephrine concentration was much higher in
the phrenicoabdominal vein than in the aorta (24-43 times). Plasma
epinephrine concentrations in the aorta and phrenicoabdominal vein were
significantly correlated (r = 0.88). This confirms that peripheral
epinephrine concentration is a reliable index of the activity of the
adrenal medulla during exercise. The epinephrine-to-norepinephrine ratio in
the phrenicoabdominal vein was stable (4:1) throughout the experimental
protocol, suggesting that the proportion of the two amines released by the
adrenal medulla did not vary through this range of adrenal activity in
dogs.
