Myocardial levels of catalase (A), total superoxide dismutase (SOD) (B), glutathione peroxidase (GPx) (C), and glutathione (GSH) (D) activity in control and exercised rats exposed to intermittent hypoxia or room air for 14 days.

<p>Values are mean±SEM; n = 5 per group. ^†<i>p</i><0.05 compared with CON-Veh; ^‡<i>p</i><0.05 compared with IHCON-Veh; ^§<i>p</i><0.05, compared with vehicle injections in all four groups (CON, IHCON, EXE, and IHEXE); ^¶<i>p</i><0.05 compared with zinc injections in all four groups. CON, controls; IHCON, intermittent hypoxia; EXE, exercise; IHEXE, IH interspersed with EXE; Veh, vehicle injection; zinc, zinc chloride injection; TPEN, N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine injection.