鞘内注射大麻酚类抑制大鼠脊髓内有毒刺激引起的Fos蛋白样免疫反应及其与吗啡的比较(英文)

Intrathecal cannabinoid administration suppresses noxious stimulus-evoked Fos protein-like immunoreactivity in rat spinal cord: comparison with morphine

AIM: To determine whether cannabinoids suppressnoxious stimulu-evoked Fos protein-like immunoreac-tivity (FLI) through direct actions at the spinal level.METHODS: Rats were implanted with intrathecal(ith) catheters at least one week prior to evaluation inthe formalin test. Effects of the cannabinoid agonist,CP55,940 (80 μg ith) on formalin pain and FLI in ratspinal cord were compared with that of the prototypicnarcotic analgesic, morphine (20 μg ith). CP55, 940suppressed pain behavior and FLI induced by intra-plantar formalin. The cannabinoid suppressed Fos inthe neck region of the dorsal horn and in the ventralhorn,but not in the nucleus proprius. The efficacy ofthe cannabinoid in suppressing FLI in these laminae

AIM: To determine whether cannabinoids suppress noxious stimulus-evoked Fos protein-like immunoreac-tivity (FLI) through direct actions at the spinal level. METHODS: Rats were implanted with intrathecal (ith) catheters at least one week prior to evaluation in the formalin test. Effects of the cannabinoid agonist, CP55,940 (80 μg ith) on formalin pain and FLI in rat spinal cord were compared with that of the prototypic narcotic analgesic, morphine (20 μg ith). CP55,940 suppressed pain behavior and FLI induced by intra-plantar formalin. The cannabinoid suppressed Fos in the neck region of the dorsal horn and in the ventral horn, but not in the nucleus proprius. The efficacy of the cannabinoid in suppressing FLI in these laminae and pain behavior was comparable to morphine administered via the same route. However, only morphine suppressed FLI in the superficial dorsal horn relative to vehicle treatment. CONCLUSION: Cannabinoids suppress nociceptive processing, in part, through actions at the spinal level. However, morphine showed greater potency and efficacy than CP55,940 in suppressing formalin-induced FLI following spinal administration.