title: Apoptosis does not contribute to the blood lymphocytopenia observed after intensive and downhill treadmill running in humans.
abstract: The lymphocytopenia that occurs during the recovery stage of exercise may be a result of apoptosis through an increased expression of CD95, a loss of the complement regulatory proteins CD55 and CD59, or both. Trained subjects completed intensive, moderate, and downhill treadmill-running protocols. Blood lymphocytes isolated before, immediately after, 1h after, and 24h after each exercise test were assessed for markers of apoptosis (Annexin-V(+), HSP60(+)), and CD55, CD59, and CD95 expression by flow cytometry. Lymphocytopenia occurred 1h after intensive and downhill running exercise, but no changes in the percentage of Annexin-V + or HSP60 + lymphocytes were found. Numbers of CD95(+), CD55(dim), and CD59(dim) lymphocytes increased immediately after intensive and downhill exercise, which were attributed to the selective mobilization and subsequent efflux of CD8(+) and CD56(+) lymphocyte subsets. No differences were found between the intensive and downhill protocols. In conclusion, apoptosis of circulating lymphocytes does not appear to contribute to exercise-induced lymphocytopenia.
authors.affiliation: Biomedicine and Sport and Exercise Science Research Group, School of Life Sciences, Napier University, Edinburgh, United Kingdom. r.simpson@napier.ac.uk
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: Geraint D
authors.initials: GD
authors.lastname: Florida-James
authors.forename: Greg P
authors.initials: GP
authors.lastname: Whyte
authors.forename: James R
authors.initials: JR
authors.lastname: Black
authors.forename: James A
authors.initials: JA
authors.lastname: Ross
authors.forename: Keith
authors.initials: K
authors.lastname: Guy
mesh_terms: D000328:Adult; D015703:Antigens, CD; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D018958:CD55 Antigens; D018957:CD59 Antigens; D002452:Cell Count; D018834:Chaperonin 60; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005434:Flow Cytometry; D006801:Humans; D008218:Lymphocytosis / Q000097:blood / Q000209:etiology*; D008231:Lymphopenia / Q000097:blood / Q000209:etiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009336:Necrosis; D012420:Running / Q000502:physiology*; D019014:fas Receptor
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D018958:CD55 Antigens; D018957:CD59 Antigens; D018834:Chaperonin 60; D019014:fas Receptor