Table 1.
Effect of N-nitro-L-arginine, haemoglobin and indomethacin on acetylcholine-induced relaxation of aortae from vehicle, daidzein- and 17β-oestradiol-treated rats
| Vehicle | Daidzein | 17β-oestradiol | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Ach | n | pEC50 | Rmax (%) | n | pEC50 | Rmax (%) | n | pEC50 | Rmax (%) |
| Control | 6 | 7.10±0.08 | 89±4 | 6 | 7.32±0.1* | 99±1* | 6 | 7.34±0.04* | 96±2* |
| L-NOARG | 6 | ND | 0# | 6 | 5.82±0.4# | 28±6#* | 6 | 5.93±0.19# | 33±5#* |
| L-NOARG+Hb | 6 | ND | 0# | 6 | 6.33±0.3# | 29±4#* | 6 | 6.16±0.26# | 28±3#* |
| Indomethacin | 6 | 7.12±0.10 | 87±4 | 6 | 7.26±0.09 | 95±2* | 6 | 7.25±0.12 | 94±3* |
| Indomethacin+L-NOARG | 6 | ND | 0# | 6 | 6.55±0.09# | 21±10#* | 6 | 6.64±0.31# | 29±4#* |
A comparison of the sensitivity (pEC50) and maximum relaxation to ACh in the absence (control) and presence of N-nitro-L-arginine (L-NOARG, 100 μM) alone, or with haemoglobin (Hb, 20 μM) in endothelium intact thoracic aortae from vehicle, daidzein- (0.2 mg kg−1 per day s.c.) and 17β-oestradiol- (0.1 mg kg−1 per day s.c.) treated rats. n=the number of experiments.
Significantly different from control ACh response in aortic rings from vehicle-treated rats (Bonferroni test, P<0.05).
Significantly different from the corresponding control ACh response within the same treatment group (Bonferroni test, P<0.05). ND=could not be calculated.