Table 1.
Respiratory frequency and tidal volume during baseline conditions (0% O2) and during exposure to two levels of hypercapnia for rats reared in 21% O2 (Control) or 60% O2 (Hyperoxia).
| Age | Treatment | n | Mass (g) | Respiratory Frequency(breaths min−1) | Tidal Volume (ml 100g−1) | ||||
|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||
| Baseline | 4% CO2 | 8% CO2 | Baseline | 4% CO2 | 8% CO2 | ||||
| P4 | Control | 20 | 10.6±0.2 | 164±4 | 166±4 | 159±5 | 0.93±0.05 | 1.22±0.07 # | 1.47±0.07 # |
| Hyperoxia | 19 | 10.3±0.3 | 129±4 * | 132±5 * | 130±4 * | 0.74±0.04 * | 0.89±0.04 *, # | 1.11±0.05 *, # | |
|
| |||||||||
| P6-7 | Control | 17 | 15.1±0.3 | 161±8 | 156±6 | 149±6 # | 0.74±0.03 | 0.94±0.04 # | 1.17±0.04 # |
| Hyperoxia | 16 | 14.8±0.4 | 132±3 * | 133±3 * | 129±2 *, # | 0.66±0.06 | 0.83±0.09 # | 1.05±0.11 # | |
|
| |||||||||
| P13-14 | Control | 18 | 32.2±1.0 | 143±5 | 172±7 # | 180±6 # | 0.75±0.02 | 1.02±0.03 # | 1.31±0.04 # |
| Hyperoxia | 15 | 29.9±0.9 | 130±5 * | 158±5 *, # | 162±5 *, # | 0.69±0.03 * | 0.88±0.04 *, # | 1.19±0.05 *, # | |
Data are expressed as mean ± SEM.
*
P<0.05 vs. Control at the same level of inspired CO2 (i.e., post hoc test for main effect of developmental treatment) and
#
P<0.05 vs. Baseline within the same developmental treatment (i.e., post hoc test for main effect of inspired CO2). Body mass did not differ between treatment groups at any age.