Journal of Applied Physiology, Vol 59, Issue 3 947-952, Copyright © 1985 by American Physiological Society
Plasma levels of renin, angiotensin II, and 6-ketoprostaglandin F1 alpha in endurance athletes
R. Fagard, R. Grauwels, D. Groeseneken, P. Lijnen, J. Staessen, L. Vanhees and A. Amery
Twelve male runners and 12 matched nonathletes performed a prolonged
uninterrupted graded exercise test on the bicycle ergometer up to
exhaustion to study blood pressure and plasma levels of renin (PRA),
vasoconstrictor angiotensin II (ANG II), and 6-ketoprostaglandin F1 alpha
(6-keto-PGF1 alpha), a metabolite of the vasodilator prostacyclin. In the
athletes work load was increased by 30 W/4 min, and in the control subjects
the increments of work load were adjusted to their lower exercise capacity
to equalize total exercise duration. Blood was drawn, and blood pressure
and O2 uptake (VO2) were measured at rest and at the fourth, eighth, and
last steps of exercise. Peak VO2 averaged 60 +/- 1.6 ml . min-1 . kg-1 in
the runners and 46.8 +/- 1.5 in the nonathletes. To evaluate differences
between athletes and controls, PRA, ANG II, and 6-keto-PGF1 alpha were
first adjusted for significant confounding factors, such as age, weight,
hematocrit, 24-h urinary sodium excretion, and O2 uptake. PRA was
significantly lower in the athletes (F = 11.2; P less than 0.01); ANG II
was not different at rest, but its rise with exercise was less steep in the
runners (F = 8.2; P less than 0.01), whereas 6-keto-PGF1 alpha was not
different between the groups (F = 1.3; NS). Despite the differences in PRA
and ANG II, however, blood pressure was similar in athletes and nonathletes
(F = 0.0; NS).
