Figure 5.

Effects of HU-308 and indomethacin on arachidonic acid (A′A)-induced swelling of the ear. The results are presented as the difference between the A′A-treated ear and the EtOH-treated ear, n = 5 for each treatment group. Mice (female Sabra) were treated with 4.5 mg of A′A (in 5 μl of EtOH), dispersed on the inner surface of one of the ears. The other ear was treated with 5 μl of EtOH. Ear swelling was assessed by measuring ear thickness with a dial thickness gauge, just before treatment, thence, every 15 min after application, for 90 min. (a) Time curve illustrating that peak swelling of the ear was achieved at about 30 min after A′A application. Vehicle, HU-308 (50 mg/kg), or indomethacin (20 mg/kg) was injected i.p. 60 min before A′A. Injection of HU-308 at 30 or 90 min before A′A yielded similar results (data not shown). (b) Effects of CB₁ and CB₂ receptor antagonists on the anti-inflammatory effect of HU-308. The CB₁ antagonist (SR1 = SR-141716A, 5 mg/kg) or the CB₂ receptor antagonist (SR2 = SR-144528, 1 mg/kg) was injected i.p., and followed 60 min afterward by HU-308 administration i.p. (50 mg/kg). A′A was administered 50 min after HU-308. *, Significantly different from vehicle-treated mice (P < 0.05); **, significantly different from vehicle-treated mice (P < 0.01); ***, significantly different from vehicle-treated mice (P < 0.001).