Maximal relaxant effect of isoprenaline in different canine arteries
| Artery | At 95% of Maximal Contraction | At 80% of Maximal Contraction | At 65% of Maximal Contraction | At 50% of Maximal Contraction | At 35% of Maximal Contraction |
|---|---|---|---|---|---|
| Coronary | 110 | 105 | 105 | 115 | 110 |
| Pulmonary | 0 | 16 | 17 | 31 | 50 |
| Splenic | 0 | 0 | 16 | 76 | 95 |
| Mesenteric | 0 | 3 | 70 | 82 | 90 |
Relaxant effects of isoprenaline were determined on rings precontracted with phenylephrine. The effect of isoprenaline was tested at five different levels of precontraction. In the coronary artery, the relaxation was larger than 100% since the tone reached a level lower than the baseline (adapted from Begonha et al., 1995).