title: Immune response to a single bout of exercise in young and elderly subjects.
abstract: The purpose of this investigation was to examine alterations in lymphocyte proliferation activity and T cell subsets following an acute bout of exercise in young and old subjects. Six young (26+/-3 years) and nine old (69+/-5 years) male subjects were tested at rest and immediately after 20 min of submaximal exercise at 50% peak work capacity. Arterial blood was sampled from an indwelling catheter for catecholamine and immunology assays. Peripheral blood lymphocytes were isolated for mitogen-induced phytohemagglutinin (PHA) proliferation capacity. Lymphocyte subsets were analyzed by dual-labeled flow cytometry. As has been shown in previous studies, baseline proliferative responsiveness was significantly lower in the old (down 22%) compared to the young subjects. In response to submaximal exercise, proliferative responsiveness to PHA increased significantly in the young subjects (up 55%), however, for the old subjects this response did not differ significantly from resting values (up 18%). The number of total lymphocytes, as well as CD4+ and CD8+ T cell subsets, at rest were lower for old subjects compared with young. Exercise-induced increases in T cell subset populations were similar across age groups. It was concluded that, while having lower initial T cell numbers and PHA responsiveness, immunoresponsiveness during a single bout of exercise is, in general, maintained in old when compared to young individuals.
authors.affiliation: Department of Kinesiology, University of Colorado, Boulder 80309, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Mazzeo
authors.forename: C
authors.initials: C
authors.lastname: Rajkumar
authors.forename: J
authors.initials: J
authors.lastname: Rolland
authors.forename: B
authors.initials: B
authors.lastname: Blaher
authors.forename: G
authors.initials: G
authors.lastname: Jennings
authors.forename: M
authors.initials: M
authors.lastname: Esler
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D002455:Cell Division; D004837:Epinephrine / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007958:Leukocyte Count; D016131:Lymphocyte Subsets; D008297:Male; D009638:Norepinephrine / Q000378:metabolism
chemical_list: D009638:Norepinephrine; D004837:Epinephrine