Table 2. Persistent hypernociception: Effect of l-NMMA, ODQ, or KT5823 on the antinociceptive effect of dipyrone, SNAP, or 8-Br-cGMP.
| Pretreatment
|
|||||
|---|---|---|---|---|---|
| Treatment | Before | After | l-NMMA | ODQ | KT |
| Dip | 14.1 ± 0.6 | 6.5* ± 0.7 | 12.7† ± 0.6 | 13.4† ± 0.5 | 14.1† ± 0.6 |
| SNAP | 15.6 ± 0.7 | 6.4* ± 0.5 | − | 14.0† ± 1.0 | 12.2† ± 1.6 |
| 8-Br-cGMP | 15.2 ± 0.6 | 7.9* ± 0.3 | − | − | 14.4† ± 0.3 |
The blockade of persistent hypernociception was affected by i.pl. treatment with dipyrone (Dip, 160 μg), SNAP (200 μg), or 8-Br-cGMP (300 μg). These treatments were given 5 days after discontinuation of PGE2 injections (Before), and responses were measured 1 h after the i.pl. treatment (After). Pretreatment with l-NMMA (50 μg) or ODQ (8 μg) was given 30 min before treatment, with the exception of KT5823 (KT, 1.5 μg), which was given 10 min before administration of antinociceptive agents. All treatments (Before and After) caused significant inhibition (*, P < 0.05). Pretreatment was significant compared with data after treatments (†, P < 0.05). The intensity of mechanical hypernociception was expressed in seconds. Data are the means (±SEM) of five animals per group.