Pharmacology. 2013 Sep 4;92(3-4):150-157. [Epub ahead of print]
Pharmacology of Cannabinoid Receptor Agonists and a Cyclooxygenase-2 Inhibitor in Rat Bone Tumor Pain.
Cui JH, Ju J, Yoon MH.
Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, Korea.
We evaluated the pharmacology of spinal selective cannabinoid (CB) receptor agonists and a cyclooxygenase-2 (COX-2) inhibitor on bone tumor pain. MRMT-1 tumor cells were injected into the tibia of female Sprague-Dawley rats. MRMT-1 tumor cells produced a bone tumor confirmed by radiologic and histological findings. Intrathecal CB1 (ACEA) and CB2 receptor (AM 1241) agonists and a COX-2 inhibitor (DuP 697) dose-dependently increased the withdrawal threshold. The calculated ED50 (nmol/l) values for ACEA, AM 1241 and DuP 697 were 0.007, 2.3 and 76.1, respectively. Reverse transcriptase polymerase chain reaction and Western blot showed that COX-2 mRNA and protein, but not CB1 or CB2 receptor, were increased in the spinal cords of rats with bone tumors. Spinal CB1 receptor and CB2 receptor agonists and COX-2 inhibitor may be useful in the management of bone tumor pain. Furthermore, CB2 receptor agonist may be more potent than CB1 receptor agonist and COX-2 inhibitor. |
