Effect of chronic treatment with Δ9-THC or WIN55,212-2 on cannabinoid-mediated behaviors
| Chronic Treatment | Acute Challenge | ED50 | Potency Ratio |
|---|---|---|---|
| mg/kg | |||
| Hypoactivity | |||
| Vehicle | Δ9-THC | 2.9 (0.8–10.7) | |
| Δ9-THC | Δ9-THC | 18.2 (14.5–22.9) | 6.3 |
| Vehicle | WIN55,212-2 | 0.29 (0.21–0.41) | |
| WIN55,212-2 | WIN55,212-2 | 20.9 (4.72–92.7) | 72 |
| Antinociception | |||
| Vehicle | Δ9-THC | 1.1 (0.4–2.5) | |
| Δ9-THC | Δ9-THC | 131 (64–268) | 119 |
| Vehicle | WIN55,212-2 | 0.31 (0.25–0.38) | |
| WIN55,212-2 | WIN55,212-2 | 15.9 (10.7–23.5) | 51 |
| Hypothermia | |||
| Vehicle | Δ9-THC | 2.0 (0.7–5.6) | |
| Δ9-THC | Δ9-THC | 106 (62–181) | 53 |
| Vehicle | WIN55,212-2 | 0.32 (0.16–0.64) | |
| WIN55,212-2 | WIN55,212-2 | 33.5 (25.9–43.3) | 105 |
ED50 values for WIN55,212-2 and Δ9-THC in vehicle- and cannabinoid-treated mice were determined as described underMaterials and Methods, using spontaneous activity, tail-flick assay, and rectal temperature to determine hypoactivity, antinociception, and hypothermia, respectively. ED50 values and potency ratios were calculated based on the data shown in Fig. 1.