AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 3 647-R652, Copyright © 1992 by American Physiological Society
Effect of physical exercise in hypobaric conditions on atrial natriuretic peptide secretion
O. Vuolteenaho, P. Koistinen, V. Martikkala, T. Takala and J. Leppaluoto
Department of Physiology, University of Oulu, Finland.
To evaluate the role of atrial natriuretic peptide (ANP) in
exercise-related cardiovascular and hormonal adjustments in hypobaric
conditions, 14 young athletes performed a maximal ergometer test in a
hypobaric chamber adjusted to simulate the altitudes of sea level and 3,000
m. Plasma immunoreactive ANP levels rose from 5.89 to 35.1 pmol/l at sea
level and rose significantly less (P less than 0.05), from 5.36 to 22.3
pmol/l, at simulated 3,000 m. Plasma immunoreactive amino-terminal peptide
of proANP (NT-proANP) levels increased to the same extent at sea level and
at simulated 3,000 m (from 240 to 481 pmol/l and from 257 to 539 pmol/l,
respectively). Plasma immunoreactive aldosterone increased significantly
less at simulated 3,000 m (P less than 0.05), but the changes in plasma
renin were similar in both conditions. Plasma immunoreactive endothelin-1
and serum erythropoietin levels remained unchanged. In conclusion, we found
a blunted ANP response to maximal exercise of ANP in acute hypobaric
exposure compared with that in normobaric conditions, but no significant
difference in the NT-proANP responses between the two conditions. The
divergence may be due to stimulation of the elimination mechanism of ANP.
