Figure 4

Lung W/D as a marker of pulmonary edema. No significant differences were observed between the 40% and 21% oxygen groups at any of the durations examined. The lung W/D of the 40% or 21% oxygen 16 week-exposure group was significantly decreased as compared to that of the pre-exposure group. Lung W/D of the 120 hour-exposure group was increased as compared to that of the pre-exposure group. Values are expressed as means ± SD; ** p < 0.01 and ⁺⁺ p < 0.01 as compared to the value of the pre-exposure group. n = 8 in the pre-exposure group; n = 8 (2 weeks), 10 (4 weeks), 5 (8 weeks) and 6 (16 weeks) in the 40% oxygen exposure groups; n = 5 (2 weeks), 8 (4 weeks), 6 (8 weeks) and 6 (16 weeks) in the 21% oxygen exposure groups; n = 5 (72 hours), 5 (96 hours) and 5 (120 hours) in the 90% oxygen exposure groups.