Fig. 2.

Mean body mass of mice over 30 days of residence in hypoxia chambers simulating 3 altitudes. By day 9, 4,500 m mice were significantly smaller (20.38 ± 1.20 g) than 3,000 m mice (22.37 ± 1.35 g), and both 4,500 m and 3,000 m mice were significantly smaller than 1,400 m mice (24.24 ± 1.35 g) (P < 0.001). This pattern remained until the end of the experiment, but the differences between the 3,000 and 4,500 m experiments were no longer significant. After 30 days, mice in the 4,500 m (23.9 ± 0.91 g) and 3,000 m (24.6 ± 1.40 g) chambers were significantly smaller than mice in the 1,400 m chamber (26.6 ± 1.34 g) (P < 0.001).