title: Regular moderate exercise training prevents decrease of CD4+ T-lymphocytes induced by a single bout of strenuous exercise in mice.
abstract: The biphasic effects of exercise training on the immune system have been studied extensively and represented by the well-known J-shaped curve with respect to training intensity. However, the relationship and interactions between "beneficial" exercise training and "harmful" strenuous exercise have not been researched. This study was designed to determine whether regular moderate exercise training could affect the changes of percentage of T-lymphocytes induced by a single bout of strenuous exercise. A protocol to run uphill on a 10 degrees tilted treadmill for 4 weeks was employed as moderate exercise training in mice, while a sedentary control group of mice was exposed to the same handling stress without training. The trained and untrained mice were then exposed to a single bout of strenuous exercise until exhaustion. Total leukocytes were collected from spleen and peripheral blood at 0 hr, 3 hrs, and 24 hrs postexhaustion, as well as from the control groups. Flow cytometric analyses were conducted to determine the percentages of selected leukocyte populations. It was demonstrated that moderate exercise training prevented the decrease of CD4+ but stimulated the increase of CD25+ CD8+ T-lymphocytes induced by a single bout of strenuous exercise, indicating an adaptive response that can affect changes of leukocyte subpopulations.
authors.affiliation: Department of Orthopaedics and Traumatology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
authors.forename: Sai Chuen
authors.initials: SC
authors.lastname: Fu
authors.forename: Lin
authors.initials: L
authors.lastname: Qin
authors.forename: Chi Kam
authors.initials: CK
authors.lastname: Leung
authors.forename: Barbara Pui
authors.initials: BP
authors.lastname: Chan
authors.forename: Kai Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000818:Animals; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D005260:Female; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D009043:Motor Activity / Q000502:physiology*; D015999:Multivariate Analysis; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D015375:Receptors, Interleukin-2