title: Plasma catecholamine and nephrine responses to brief intermittent maximal intensity exercise.
abstract: Catecholamines (noradrenaline, NA; adrenaline, AD; dopamine, DA) influence the metabolic and cardiovascular responses to exercise. However, changes in catecholamine metabolism during exercise are unclear. Plasma normetanephrine (NMET), metanephrine (MET) and catecholamine responses to a laboratory-based model of games-type exercise were examined. Twelve healthy men completed a resting control trial and a trial consisting of ten 6 s cycle ergometer sprints interspersed with 30 s recovery, in randomised order. Resting and post-sprint venous blood samples were taken. Plasma NA and AD increased after each sprint but DA was unaltered. Plasma nephrines increased significantly from sprint 4 onwards with peak NMET increasing 60% to 0.76 +/- 0.19 nmol l(-1) and MET 230% to 0.37 +/- 0.16 nmol l(-1) from resting values (P < 0.05). The results demonstrate increased catecholamine metabolism via elevated catechol-O-methyl transferase activity during intermittent sprinting. The results may aid regulation of the metabolic and cardiovascular responses to exercise by maintaining tissue adrenoceptor sensitivity to circulating catecholamines.
authors.affiliation: Research Centre for Sport and Exercise Science, School of Human Sciences, Swansea University, Singleton Park, Swansea SA2 8PP, UK. R.M.Bracken@swansea.ac.uk
authors.forename: Richard M
authors.initials: RM
authors.lastname: Bracken
authors.forename: Denise M
authors.initials: DM
authors.lastname: Linnane
authors.forename: Stephen
authors.initials: S
authors.lastname: Brooks
mesh_terms: D001642:Bicycling / Q000502:physiology; D002394:Catechol O-Methyltransferase / Q000097:blood; D002395:Catecholamines / Q000097:blood*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008676:Metanephrine / Q000097:blood*; D009647:Normetanephrine / Q000097:blood*; D055815:Young Adult
chemical_list: D002395:Catecholamines; D009647:Normetanephrine; D008676:Metanephrine; D002394:Catechol O-Methyltransferase