Differential effects of repeated low dose treatment with the cannabinoid agonist WIN 55,212-2 in experimental models of bone cancer pain and neuropathic pain

TY - JOUR

T1 - Differential effects of repeated low dose treatment with the cannabinoid agonist WIN 55,212-2 in experimental models of bone cancer pain and neuropathic pain

AU - Hald, Andreas

AU - Ding, Ming

AU - Egerod, Kristoffer Lihme

AU - Hansen, Rikke Rie

AU - Konradsen, Dorthe

AU - Jørgensen, Stine G.

AU - Atalay, Baris

AU - Nasser, Arafat

AU - Bjerrum, Ole Jannik

AU - Heegaard, Anne-Marie

PY - 2008

Y1 - 2008

N2 - Pain due to bone malignancies is one of the most difficult types of cancer pain to fully control and may further decrease the patients' quality of life. Animal models of chronic pain conditions resulting from peripheral inflammatory reactions or nerve injuries are responsive to treatment with cannabinoid agonists. However, the use of cannabinoid agonists in humans may be hampered by CNS related side effects and development of tolerance. In the present study, we investigated the effect of repeated low dose administration of the synthetic cannabinoid agonist WIN 55,212-2 on bone cancer pain and neuropathic pain in mice. In addition, we investigated the development of CNS related side effects and tolerance. We found that 0.5 mg/kg/day for 18 days reduced pain related behavior and expression of spinal glial fibrillary acidic protein in the bone cancer pain model but not in the neuropathic pain model. Furthermore, this treatment strategy was not found to induce measurable CNS related side effects or tolerance. Cancer cell viability assays and bone volume fraction assessed by micro computed tomography (microCT) demonstrated that these effects were not due to changes in cancer progression. The difference in WIN 55,212-2 efficacy between the bone cancer and neuropathic pain models may reflect the different pain generating mechanisms, which may be utilized in designing new therapeutic drugs.

AB - Pain due to bone malignancies is one of the most difficult types of cancer pain to fully control and may further decrease the patients' quality of life. Animal models of chronic pain conditions resulting from peripheral inflammatory reactions or nerve injuries are responsive to treatment with cannabinoid agonists. However, the use of cannabinoid agonists in humans may be hampered by CNS related side effects and development of tolerance. In the present study, we investigated the effect of repeated low dose administration of the synthetic cannabinoid agonist WIN 55,212-2 on bone cancer pain and neuropathic pain in mice. In addition, we investigated the development of CNS related side effects and tolerance. We found that 0.5 mg/kg/day for 18 days reduced pain related behavior and expression of spinal glial fibrillary acidic protein in the bone cancer pain model but not in the neuropathic pain model. Furthermore, this treatment strategy was not found to induce measurable CNS related side effects or tolerance. Cancer cell viability assays and bone volume fraction assessed by micro computed tomography (microCT) demonstrated that these effects were not due to changes in cancer progression. The difference in WIN 55,212-2 efficacy between the bone cancer and neuropathic pain models may reflect the different pain generating mechanisms, which may be utilized in designing new therapeutic drugs.

KW - Former Faculty of Pharmaceutical Sciences

U2 - 10.1016/j.pbb.2008.04.021

DO - 10.1016/j.pbb.2008.04.021

M3 - Journal article

C2 - 18611408

SN - 0091-3057

VL - 91

SP - 38

EP - 46

JO - Pharmacology, Biochemistry and Behavior

JF - Pharmacology, Biochemistry and Behavior

IS - 1

ER -