Korean J Pain.  2005 Dec;18(2):133-137. 10.3344/kjp.2005.18.2.133.

Study for the Antinociceptive Effect and Toxicity of Chronic Intrathecal Infusion of Cannabinoids in Rats

• Yoon MH
• Bae HB
• Choi JI
• Bae CS
• Kim SJ
• Kim CM
• Jeong ST
• Kim KS
• Jin WJ
• Kim JP
• Kim JS

• KMID: 2277975
• DOI: http://doi.org/10.3344/kjp.2005.18.2.133

Abstract

BACKGROUND
Cannabinoids have shown antinociceptive action. The aims of this study were to examine the effect of chronic infusion of a cannabinoids receptors agonist (WIN 55, 212-2) for thermal nociception at the spinal level, and to also observe the development of toxicity. METHODS: Male Sprague-Dawley rats were implanted with lumbar intrathecal catheters with the nociceptive response (withdrawal response latency) determined by exposing the plantar surface of the hindpaw to radiant heat. Initially, the effect of intrathecal WIN 55, 212-2 was evaluated followed by the change in the effect at 1, 2, 3 and 4 weeks after repeated infusion. Finally, the histopathological findings were assessed 1 and 4 weeks following the infusion of WIN 55, 212-2. RESULTS: Intrathecal WIN 55, 212-2 was found to produce a limited antinociception during the thermal test. %MPE of WIN 55, 212-2 at 1, 2, 3, and 4 weeks after infusion was not different from each other. No abnormal pathological findings were observed following a chronic intrathecal infusion of WIN 55, 212-2. CONCLUSIONS: WIN 55, 212-2, a cannabinoids receptors agonist, may be useful in the management of thermal nociception, without changing the effectiveness or causing the toxicity following a chronic infusion at the spinal level.

Keyword

cannabinoids; chronic; intrathecal; rat; thermal test; toxicity

MeSH Terms

Animals
Cannabinoids*
Catheters
Hot Temperature
Humans
Male
Nociception
Rats*
Rats, Sprague-Dawley
Cannabinoids