Table 3.
Antinociceptive effects of cannabinoid CB2 agonists in the carrageenan model of inflammation
| Pain model | Drugs |
Route of administration |
Pharmacological specificity |
Antinociception |
Mediated by |
Studies | |||
|---|---|---|---|---|---|---|---|---|---|
| Systemic | Local | CB1 (local/systemic) | CB2 (local/systemic) | CB1 | CB2 | Reference | |||
| Inflammatory | |||||||||
| •Carrageenan i.pl. post | GW405833 (L768242) | 0.3–10 mg kg−1, i.p. | — | NT | Blocked by SR144528; 3 mg kg−1, i.p. | Yes WB |
NT | Yes | Clayton et al., 2002 |
| •Carrageenan i.pl. post | AM1241 | 33–330 μg kg−1, i.p. | 33 μg kg−1, i.pl. | Not blocked by SR141716A; 1 mg kg−1, i.p. | Blocked by SR144528; 1 mg kg−1, i.p. | Yes M and T Fos |
No | Yes | Nackley et al., 2003a |
| •Carrageenan i.paw pre | AM1241 | 0.1–1 mg kg−1, i.p. | 1–4 mg kg−1, i.paw | Not blocked by AM251; 300 μg kg−1, i.p.; 300 mg kg−1, i.paw | Blocked by AM630; 100 μg kg−1 i.p.; 100 μg kg−1, i.paw | Yes T |
No | Yes | Quartilho et al., 2003 |
| •Carrageenan i.pl. post | AM1241 | 330 μg kg−1, i.v. | 33 or 330 μg kg−1, i.pl. | Not blocked by SR141716A; 1 mg kg−1, i.v. | Blocked by SR144528; 1 mg kg−1, i.v. | Yes NP (E) Inf >Noninf |
No | Yes | Nackley et al., 2004 |
| •Carrageenan i.pl. pre | JWH-133 | — | 5–15 μg in 50 μl, i.pl. | Not blocked by SR141716A; 10 μg in 50 μl i.pl. | Blocked by SR144528; 10 μg in 50 μl i.pl. | Yes NP (M) Inf≈Noninf |
No | Yes | Elmes et al., 2004 |
| •Carrageenan i.pl. pre | JWH-133 | 0.3–10 mg kg−1, s.c. | — | Not blocked by SR141716A; 3 mg kg−1, s.c. | Blocked by SR144528; 3 mg kg−1, s.c. | Yes WB |
No | Yes | Elmes et al., 2005 |
| •Carrageenan i.pl. pre | AM1241 | — | 33 μg kg−1, i.pl. | Not blocked by SR141716A; 33 μg kg−1, i.pl. | Blocked by SR144528; 33 μg kg−1, i.pl. | Yes M and T M > T |
No | Yes | Gutierrez et al., 2007 |
| •Carrageenan i.pl. pre | AM1241 | 1–10 mg kg−1, i.p. | — | NT | Blocked by AM630; 1 mg kg−1, i.p. | Yes T |
NT | Yes | Bingham et al., 2007 |
Abbreviations: Fos, suppression of carrageenan-evoked spinal Fos protein in lamina I, II and V, VI; Inf, inflamed; i.p., intraperitoneal; i.paw, dorsal surface of the paw; i.pl., intraplantar; i.v., intravenous; E, transcutaneous electical stimulation; M, mechanical; Noninf, noninflamed; NP, neurophysiological evidence from extracellular recordings of spinal wide dynamic range neurons; NT, not tested; post, carrageenan injected after drugs; pre, carrageenan injected before drugs; s.c., subcutaneous; T, thermal; WB, weight bearing.
•Tested on rats □ .