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document
Hypoxic exercise training reduces senescent T-lymphocyte subsets in blood . The integration and control of systemic immune responses depends on the regulated trafficking of T-lymphocytes . This study elucidates how various exercises regimens with/without hypoxia affect phenotypic characteristics of T-lymphocyte subsets in blood . Fifty sedentary males were randomly divided into five groups . Each group ( n=10 ) received one of five interventions : normoxic ( 21 % O₂ ) resting ( N-C ) , hypoxic ( 15 % O₂ ) resting ( H-C ) , normoxic exercise ( 50 % W ( max ) under 21 % O₂ , N-T ) , hypoxic-relative exercise ( 50 % maximal heart rate reserve under 15 % O₂ , H-RT ) , or hypoxic-absolute exercise ( 50 % W ( max ) under 15 % O₂ , H-AT ) for 30 min/day , 5 days/week for 4 weeks . Before the intervention , strenuous exercise up to exhaustion increased the mobilization of CD3 , CD4 , CD8 , or CD8 ( bright ) lymphocytes expressing activated ( CD11a ) or senescent ( KLRG1 ) molecules into the peripheral blood compartment . The H-AT for 4 weeks up-regulated co-stimulatory molecule CD28 expression and was accompanied by depressed KLRG1 level on CD3 , CD4 , CD8 , or CD8 ( bright ) lymphocytes at rest or following exercise . Simultaneously , this intervention increased interferon-γ ( IFN-γ ) level and unchanged interleukin-4 level , as well as , decreased myeloperoxidase ( MPO ) and interleukin-6 levels in plasma . However , no significant changes in resting and exercise-induced mobilizations of various T-lymphocyte subsets and productions of cytokines and MPO occurred following the N-C , H-C , N-T , and H-RT interventions . Therefore , we conclude that 4-week H-AT intervention reduced senescent T-lymphocyte subsets with increasing IFN-γ level in blood , which responses are accompanied by depressed oxidative stress and pro-inflammatory cytokine production . These findings can help to determine an effective hypoxic exercise regimen to minimize immune dysfunction by retarding T-lymphocyte senescence .
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Intervention_Educational
Hypoxic exercise training
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Outcome_Physical
senescent T-lymphocyte subsets in blood
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Outcome_Physical
phenotypic characteristics of T-lymphocyte subsets in blood
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Participant_Sample-size
Fifty
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Participant_Condition
sedentary
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Participant_Sex
males