Table 2.
Arterial hydrogen ion concentration, arterial pH, bicarbonate concentration, base excess, and plasma potassium concentration in controls with acetazolamide iv, acetazolamide po, inhaled acetazolamide, methazolamide iv, and N-methyl-acetazolamide iv during normoxia and hypoxia
| n | Normoxia 1 h | Hypoxia 1st h | Hypoxia 2nd h | |
|---|---|---|---|---|
| H+, nM/l | ||||
| Series 1 | ||||
| Controls | 7 | 41.3 ± 1.7 | 35.4 ± 2.6* | 34.8 ± 2.7* |
| ACZ iv | 7 | 41.0 ± 1.7 | 38.0 ± 2.8 | 38.5 ± 2.4*† |
| ACZ po | 7 | 44.3 ± 1.7 | 39.7 ± 1.5*† | 38.4 ± 1.4*† |
| ACZ inhaled | 7 | 42.2 ± 1.6 | 36.9 ± 1.3* | 35.8 ± 1.8* |
| Series 2 | ||||
| Controls | 9 | 41.6 ± 1.7 | 35.0 ± 1.4 | 34.1 ± 1.0 |
| ACZ iv | 8 | 41.2 ± 1.4 | 37.5 ± 1.9 | 38.0 ± 1.5 |
| MTZ iv | 6 | 39.5 ± 1.3 | 35.6 ± 1.9 | 36.0 ± 2.2 |
| NMA iv | 6 | 42.0 ± 1.5 | 34.8 ± 1.6 | 34.4 ± 1.9 |
| pHa | ||||
| Series 1 | ||||
| Controls | 7 | 7.384 | 7.451* | 7.458* |
| ACZ iv | 7 | 7.387 | 7.420 | 7.414*† |
| ACZ po | 7 | 7.353 | 7.402*† | 7.416*† |
| ACZ inhaled | 7 | 7.375 | 7.433* | 7.446* |
| Series 2 | ||||
| Controls | 9 | 7.381 | 7.456* | 7.468* |
| ACZ iv | 8 | 7.385 | 7.425*† | 7.420*† |
| MTZ iv | 6 | 7.404 | 7.448* | 7.444* |
| NMA iv | 6 | 7.376 | 7.458* | 7.463* |
| HCO3−, mM | ||||
| Series 1 | ||||
| Controls | 7 | 21.7 ± 1.7 | 19.2 ± 2.6 | 19.6 ± 3.7 |
| ACZ iv | 7 | 19.8 ± 1.0 | 18.1 ± 1.2 | 16.9 ± 1.0 |
| ACZ po | 7 | 17.5 ± 0.9† | 17.6 ± 1.4 | 16.8 ± 1.7 |
| ACZ inhaled | 7 | 20.5 ± 1.4 | 17.2 ± 1.8* | 16.7 ± 1.4*† |
| Series 2 | ||||
| Controls | 9 | 21.0 ± 1.5 | 20.0 ± 1.6 | 19.5 ± 1.4 |
| ACZ iv | 8 | 19.2 ± 1.1 | 17.9 ± 1.2† | 16.2 ± 1.3*† |
| MTZ iv | 6 | 20.3 ± 1.4 | 18.0 ± 1.2* | 17.4 ± 1.5* |
| NMA iv | 6 | 21.3 ± 1.2 | 19.2 ± 1.5 | 18.9 ± 1.5* |
| BE, mM | ||||
| Series 1 | ||||
| Controls | 7 | −2.3 ± 1.7 | −2.3 ± 2.0 | −2.3 ± 3.1 |
| ACZ iv | 7 | −4.0 ± 1.0 | −4.6 ± 1.0 | −5.8 ± 1.0† |
| ACZ po | 7 | −6.8 ± 0.8† | −5.7 ± 1.0† | −6.0 ± 1.0† |
| ACZ inhaled | 7 | −3.6 ± 1.3 | −5.1 ± 1.7† | −5.2 ± 1.5† |
| Series 2 | ||||
| Controls | 9 | −3.1 ± 1.4 | −2.2 ± 1.5 | −2.9 ± 2.0 |
| ACZ iv | 8 | −4.4 ± 1.0† | −4.6 ± 1.4† | −6.2 ± 1.4† |
| MTZ iv | 6 | −3.1 ± 1.2 | −4.1 ± 1.4 | −4.7 ± 1.7 |
| NMA iv | 6 | −2.9 ± 1.1 | −2.8 ± 1.5 | −3.0 ± 1.6 |
| PK, mM | ||||
| Series 1 | ||||
| Controls | 7 | 3.5 ± 0.2 | 3.3 ± 0.3 | 3.2 ± 0.2 |
| ACZ iv | 7 | 3.0 ± 0.2 | 2.9 ± 0.3 | 2.8 ± 0.3 |
| ACZ po | 7 | 2.9 ± 0.2† | 2.9 ± 0.1 | 2.8 ± 0.2 |
| ACZ inhaled | 7 | 3.2 ± 0.3 | 3.1 ± 0.3 | 3.1 ± 0.3 |
| Series 2 | ||||
| Controls | 9 | 3.5 ± 0.2 | 3.4 ± 0.2 | 3.3 ± 0.2 |
| ACZ iv | 8 | 3.2 ± 0.2 | 3.1 ± 0.3 | 3.0 ± 0.2 |
| MTZ iv | 6 | 3.2 ± 0.2 | 3.0 ± 0.3 | 2.8 ± 0.2† |
| NMA iv | 6 | 3.5 ± 0.4 | 3.3 ± 0.5 | 3.1 ± 0.3 |
Values are mean ± SD; n, no. of experiments.
H+, arterial hydrogen ion concentration; pHa, arterial pH; HCO3−, arterial bicarbonate concentration; BE, base excess; PK, plasma potassium concentration.
Significant differences (P < 0.05) vs.
*
normoxia and
†
controls at equal time points.