Longitudinal changes in plasma thiol, REDST, HVR, EPO level, and plasma peroxide concentration.

Longitudinal changes during NAC treatment and prolonged poikilocapnic hypoxia. Values are means ± SEM of the data before (day 1) and after 4 days of treatment (day 5) and the data on day 6 before, during, and after a 6-hour exposure to prolonged hypoxia indicated by the windows. The 6-hour exposition to normobaric hypoxia on day 6 started at 10 am. Three subjects (all placebo) of the total group (n = 26) refused to participate in the hypoxic exposition. Significant differences between the NAC group (●) and the placebo group (○) (*P < .05; **P < .01), significant changes compared with corresponding time points on day 1 (#P < .05; ##P < .01), and significant posthypoxic changes compared with the last value in hypoxia (day 6, 3:30 pm) ($P < .05; $$ P < .01) are indicated.