Table 1.
Mean steady-state values for blood gas, ventilatory, and EMGdi variables
| Dog No. | PaCO2, Torr | PaO2, Torr | pHa | [HCO3−], meq/l | V̇i, l/min | Vt, liter | f, breaths/min | Ti, s | Te, s | EMGdi, AU |
|---|---|---|---|---|---|---|---|---|---|---|
| Control | ||||||||||
| 1 | 46.4±2.9 | 92.6±3.2 | 7.30±0.02 | 22.1±1.4 | 3.27±0.59 | 0.23±0.05 | 14.8±4.2 | 1.56±0.26 | 2.94±1.13 | 0.35±0.33 |
| 2 | 36.0±1.3 | 104.1±6.7 | 7.35±0.01 | 19.4±0.2 | 5.05±0.40 | 0.31±0.03 | 16.5±0.5 | 1.24±0.13 | 2.43±0.08 | 0.58±0.07 |
| 3 | 48.4±2.7 | 87.0±5.3 | 7.33±0.02 | 24.8±1.7 | 5.33±0.79 | 0.42±0.19 | 16.0±6.5 | 2.42±1.55 | 1.90±0.50 | |
| 4 | 41.1±1.0 | 99.6±9.8 | 7.34±0.02 | 21.4±0.6 | 3.85±0.46 | 0.26±0.02 | 14.2±1.9 | 1.55±0.09 | 2.79±0.49 | 0.46±0.28 |
| Mean±SD | 43.0±5.6 | 95.8±7.6 | 7.33±0.02 | 21.9±2.2 | 4.38±0.98 | 0.31±0.08 | 15.4±1.1 | 1.69±0.51 | 2.52±0.46 | 0.46±0.12 |
| CB perfused normoxic-normocapnic | ||||||||||
| 1 | 43.9±0.1 | 97.3±1.9 | 7.29±0.03 | 20.4±1.3 | 3.90±0.50 | 0.26±0.03 | 15.1±3.6 | 1.60±0.07 | 2.60±0.96 | 0.34±0.06 |
| 2 | 38.8±1.8 | 94.7±0.7 | 7.33±0.03 | 19.9±0.3 | 4.56±0.18 | 0.28±0.02 | 16.5±1.9 | 1.23±0.18 | 2.46±0.24 | 0.54±0.01 |
| 3 | 48.5±1.9 | 91.4±2.7 | 7.31±0.01 | 23.6±1.5 | 5.13±1.34 | 0.53±0.16 | 9.7±0.3 | 3.70±1.60 | 2.55±1.38 | |
| 4 | 40.7±0.8 | 101.0±4.8 | 7.33±0.02 | 20.6±0.4 | 3.78±0.76 | 0.27±0.02 | 13.3±1.8 | 1.69±0.05 | 3.38±0.81 | 0.47±0.25 |
| Mean±SD | 43.0±4.2 | 96.1±4.1 | 7.32±0.02 | 21.1±1.7 | 4.34±0.63 | 0.34±0.13 | 13.7±2.9 | 2.06±1.11 | 2.75±0.43 | 0.45±0.10 |
| CB perfused hyperoxic-hypocapnic | ||||||||||
| 1 | 60.4±3.2 | 91.2±4.7 | 7.24±0.02 | 24.4±0.41 | 1.70±0.56 | 0.18±0.03 | 10.1±3.9 | 1.64±0.27 | 5.36±2.58 | 0.23±0.03 |
| 2 | 45.5±3.2 | 100.4±5.0 | 7.28±0.02 | 20.5±24.4 | 3.77±1.70 | 0.27±0.03 | 14.1±3.9 | 1.38±0.27 | 2.90±2.58 | 0.47±0.07 |
| 3 | 57.1±2.2 | 89.3±5.1 | 7.29±0.02 | 26.1±1.83 | 4.46±0.49 | 0.22±0.08 | 18.4±7.5 | 2.46±2.06 | 1.60±0.39 | |
| 4 | 47.7±1.2 | 97.5±3.4 | 7.27±0.02 | 20.4±2.10 | 2.52±0.73 | 0.26±0.02 | 11.6±3.5 | 2.00±0.67 | 3.47±0.96 | 0.37±0.17 |
| Mean±SD | 52.7±7.2*† | 94.6±5.2 | 7.27±0.02*† | 22.9±2.9 | 3.11±1.24*† | 0.26±0.04*† | 13.6±3.6 | 1.87±0.47 | 3.33±1.56 | 0.36±0.12*† |
Values are means ± SD. CB, carotid body; PaCO2, arterial Pco2; PaO2, arterial Po2; pHa, arterial pH; [HCO3−], HCO3− concentration; V̇i, ventilation; Vt, tidal volume; f, breathing frequency; Ti, inspiratory time; Te, expiratory time; EMGdi, moving-time-averaged electromyogram of the costal diaphragm; AU, arbitrary units. Blood gases during CB perfusion are from the last (steady-state) blood sample. Note that 1) control refers to the condition following the second surgery (denervation of one CB; see methods); 2) for CB, perfused hyperoxic-hypocapnic inspired O2 fraction was increased to maintain PaO2 at control values.
Significant difference from control values, P < 0.05.
Significant difference from CB normal values, P < 0.05.