Table 3.
Relaxations induced by acetylcholine and SIN-1 U46619 (10−7 M)-contracted proximal and distal pulmonary arteries isolated from normoxic (N) and hypoxic (H) rats, and hypoxic rats treated with tempol (HT), molsidomine (HM), and tempol plus molsidomine (HTM)
| Acetylcholine | SIN-1 | ||||
|---|---|---|---|---|---|
| n | pD2 | Max. relaxation (%) | pD2 | Max relaxation (%) | |
| Proximal | |||||
| N | 8 | 7.16±0.31 | 80.4±1.9 | 4.99±0.05 | 85.8±3.7 |
| H | 8 | 6.91±0.09 | 33.8±3.0* | 4.80±0.11 | 52.6±6.4* |
| HT | 8 | 7.33±0.18 | 40.9±7.6* | 4.91±0.10 | 59.7±9.0 |
| HM | 5 | 7.00±0.22 | 26.8±6.4* | 5.13±0.20 | 50.6±5.3* |
| HTM | 7 | 6.36±0.60 | 33.6±4.6* | 4.67±0.12 | 54.5±7.8* |
| Distal | |||||
| N | 9 | 6.23±0.34 | 49.8±5.2 | 4.86±0.16 | 73.1±4.9 |
| H | 8 | 6.29±0.21 | 32.9±5.4 | 4.79±0.15 | 66.4±7.1 |
| HT | 8 | 6.96±0.23 | 51.8±17.3 | 5.21±0.02 | 55.8±11.8 |
| HM | 7 | 6.50±0.23 | 25.9±7.0 | 5.09±0.08 | 63.9±5.1 |
| HTM | 7 | 6.33±0.58 | 22.4±4.8 | 5.25±0.28 | 53.3±10.9 |
Values are mean±s.e.m. of n number of preparations examined.
*
P<0.05, parameter significantly different from normoxic animal, pD2=−log EC50, where EC50 is the concentration of agonist producing half-maximal relaxation.