The effect of prior exercise on ex vivo induction of heme oxygenase-1 in human lymphocytes

It was postulated that prior demanding exercise would suppress the induction of the oxidant-responsive protein Heme Oxygenase-1 (HO-1) in mononuclear cells following subsequent ex vivo H O-2(2) treatment. Eight male subjects completed two trials in a randomized order (one rest and one exercise) and ex vivo HO-1 protein induction was determined following H2O2 treatment in lymphocytes and monocytes before and after each trial using a newly developed and reproducible assay. Lymphocytes obtained 2 h post-exercise showed a modest reduction in HO-1 protein expression in response to ex vivo treatment with H2O2 (pB0.05). The plasma concentration of the HO-1 suppressor alpha 1-antitrypsin increased immediately post- exercise (pB0.05) and it is tentatively suggested that this may explain the modest transient reduction in ex vivo HO-1 protein induction in lymphocytes in response to an independent oxidant challenge following a prior bout of demanding exercise.