ISSN:
1439-6327
Keywords:
Aldosterone
;
Plasma volume
;
Osmolality
;
Sodium
;
Heart rate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The present study was designed to investigate the influence of exercise intensity and duration as well as of inspiratory oxygen content on plasma atrial natriuretic peptide concentration ([ANP]) and furthermore to compare ANP with the effect on aldosterone concentration ([Aldo]). Ten untrained male subjects performed a maximal exercise test (ME) on a cycle ergometer and a submaximal test of 60-min duration at 60% of maximal performance (SE) under normoxia (N) and normobaric hypoxia (H) (partial pressure of oxygen: 12.3 kPa). Five subjects were exposed to hypoxia at rest for 90 min. The [ANP] was mostly affected by exercise intensity (5 min after ME-N, +298.1%, SEM 39.1%) and less by exercise duration (at the end of SE-N: +229.5%, SEM 33.2%). Hypoxia had no effect at rest and reduced the exercise response (ME-H, +184.3%, SEM 27.2%; SE-H, +172.4%, SEM 15.7%). In contrast to ANP, the Aldo response was affected more by duration at submaximal level (+290.1%, SEM 34.0%) than by short maximal exercise (+235.7%, SEM 22.2%). Exposure to hypoxia rapidly decreased [Aldo] (−28.5%, SEM 3.7% after 30 min, P〈0.01), but did not influence the exercise effects (ME-H, +206.2%, SEM 26.4%; SE-H, +321.6%, SEM 51.6%). The [ANP] increase was faster than that of [Aldo] during the maximal tests and there was no difference during submaximal exercise. Changes in plasma volume (PV), sodium concentration, and osmolality (Osm) were most pronounced during maximal exercise (for ME-N: PV −13.1%, SD 3.6%, sodium +6.2 mmol·1−1, SD 2.7, Osm +18.4 mosmol·kg H2O−1, SD 6.5). Regression analysis showed high correlations between changes in [ANP] and in Osm during and after maximal exercise and between changes in [ANP] and heart rate for submaximal exercise. It is concluded that besides other mechanisms increased Osm might be involved in the exercise-dependent increase of plasma [ANP].
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00236059
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