title: Atrial natriuretic peptide during and after maximal and submaximal exercise under normoxic and hypoxic conditions.
abstract: 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 less than 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.l-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].
authors: Abteilung für Sport- und Arbeitsphysiologie, Medizinische Hochschule Hannover, Federal Republic of Germany.
authors: W
authors: W
authors: Schmidt
authors: G
authors: G
authors: Brabant
authors: C
authors: C
authors: Kröger
authors: S
authors: S
authors: Strauch
authors: A
authors: A
authors: Hilgendorf
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D009994:Osmolar Concentration; D012044:Regression Analysis; D012964:Sodium / Q000097:blood
chemical_list: D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012964:Sodium