title: Plasma levels of polymorphonuclear elastase and myeloperoxidase after uphill walking and downhill running at similar energy cost.
abstract: This study was designed to compare the effects of eccentric and concentric exercises on blood polymorphonuclear neutrophil count (nPMN) and plasma levels of myeloperoxidase ([MPO]) and elastase ([EL]) used as markers of neutrophil (PMN) activation. Ten healthy male subjects underwent 2 periods of exercise of 20 min duration each at 60% VO2max on an inclined treadmill. They initially walked up a 5% grade (UW). Ten days later they ran downhill on a 20% grade (RD). Blood samples were collected 10 min before and immediately after exercise. A postexercise sample was drawn after 20 min recovery. Both exercise bouts were accompanied by a similar and significant (p < 0.01) increase of 33% in nPMN above resting values. Baseline nPMN values were reached after 20 min recovery. There were no significant changes in [MPO] and [EL] following UW. In contrast, RD was followed by significant increases (p < 0.001) in [MPO] (+97%) and [EL] (+70%) above resting levels. While [MPO] returned to its pre-exercise level after 20 min recovery, [EL] remained significantly elevated (p < 0.05). These results clearly demonstrate the importance of the eccentric component of muscle contraction in exercise-induced PMN activation.
authors.affiliation: FNRS, Laboratory of Human Applied Physiology, ISEPK, University of Liège, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Camus
authors.forename: J
authors.initials: J
authors.lastname: Pincemail
authors.forename: M
authors.initials: M
authors.lastname: Ledent
authors.forename: A
authors.initials: A
authors.lastname: Juchmès-Ferir
authors.forename: M
authors.initials: M
authors.lastname: Lamy
authors.forename: G
authors.initials: G
authors.lastname: Deby-Dupont
authors.forename: C
authors.initials: C
authors.lastname: Deby
mesh_terms: D000293:Adolescent; D000328:Adult; D004734:Energy Metabolism / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009504:Neutrophils / Q000201:enzymology*; D010101:Oxygen Consumption / Q000502:physiology; D010196:Pancreatic Elastase / Q000097:blood*; D009195:Peroxidase / Q000097:blood*; D012420:Running / Q000502:physiology*; D016138:Walking / Q000502:physiology*
chemical_list: D009195:Peroxidase; D010196:Pancreatic Elastase