Journal of Applied Physiology, Vol 70, Issue 3 979-987, Copyright © 1991 by American Physiological Society
Plasma atriopeptin response to prolonged cycling in humans
H. Perrault, M. Cantin, G. Thibault, G. R. Brisson, G. Brisson and M. Beland
Department of Physical Education, McGill University, Montreal, Quebec, Canada.
The exercise-induced increase in plasma atriopeptin (ANP) has been related
to exercise intensity. The independent effect of duration on the ANP
response to dynamic exercise remains incompletely documented. The purpose
of this study was to describe the time course of plasma ANP concentration
during a 90-min cycling exercise protocol and to examine this in light of
concurrent variations in plasma arginine vasopressin (AVP), aldosterone
(ALD), and catecholamine (norepinephrine and epinephrine) concentrations as
well as plasma renin activity (PRA). Seven male and four female healthy
college students (23 +/- 2 yr) completed a prolonged exercise protocol on a
cycle ergometer at an intensity of 67% of maximal O2 uptake. Venous blood
was sampled through an indwelling catheter at rest, after 15, 30, 45, 60,
and 90 min of exercise, and after 30 min of passive upright recovery.
Results (means +/- SE) indicate an increase in ANP from rest (22 +/- 2.6
pg/ml) at 15 min of exercise (45.3 +/- 7.4 pg/ml) with a further increase
at 30 min (59.4 +/- 9.8 pg/ml) and a leveling-off thereafter until
completion of the exercise protocol (51.7 +/- 10.7 pg/ml). In plasma ALD
and PRA, a significant increase was found from rest (ALD, 21.4 +/- 6.4
ng/dl), PRA, 2.5 +/- 0.5 ng.ml-1.h-1 after 30 min of cycling, which
continued to increase until completion of the exercise (ALD 46.6 +/- 8.7
ng/dl, PRA 9.5 +/- 0.9 ng.ml-1.h-1.(ABSTRACT TRUNCATED AT 250 WORDS)
