Differences between orofacial inflammation and cancer pain.

Abstract

Rat models of orofacial cancer exhibit both allodynia and hyperalgesia; however, it is unclear whether cancer-induced pain is secondary to cancer-induced inflammation. To address this question, we compared the effects of an anti-inflammatory drug, indomethacin, on pain and neurochemical changes in the medullary dorsal horn in orofacial inflammation and cancer models. Daily peripheral administration of indomethacin largely suppressed mechanical allodynia and thermal hyperalgesia in the inflammation model. The same procedure suppressed allodynia and hyperalgesia in the cancer model, but the suppression was weak when compared with that in the inflammation model. In the medullary dorsal horn, calcitonin gene-related peptide and substance P levels were significantly increased in the inflammation model, but did not change in the cancer model. These results suggest that pain in the orofacial cancer model is not significantly mediated by cancer-induced peripheral inflammation, although it may have some involvement.

• Authors: N Harano, K Ono, K Hidaka, A Kai, O Nakanishi, K Inenaga
• Journal: Journal of dental research (J Dent Res) Vol. 89 Issue 6 Pg. 615-20 (Jun 2010) ISSN: 1544-0591 [Electronic] United States
• PMID: 20332329 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Inflammatory Agents, Non-Steroidal
• Neuropeptides
• Neurotransmitter Agents
• Substance P
• Galanin
• Calcitonin Gene-Related Peptide
• Indomethacin

Topics

• Animals
• Anti-Inflammatory Agents, Non-Steroidal (administration & dosage, therapeutic use)
• Calcitonin Gene-Related Peptide (analysis, drug effects)
• Carcinoma 256, Walker (physiopathology)
• Disease Models, Animal
• Facial Neoplasms (drug therapy, physiopathology)
• Facial Pain (drug therapy, physiopathology)
• Galanin (analysis, drug effects)
• Hot Temperature
• Hyperalgesia (drug therapy, physiopathology)
• Indomethacin (administration & dosage, therapeutic use)
• Inflammation (physiopathology)
• Injections, Intraperitoneal
• Male
• Neuropeptides (analysis, drug effects)
• Neurotransmitter Agents (analysis)
• Pain Threshold (drug effects, physiology)
• Physical Stimulation
• Rats
• Rats, Wistar
• Reaction Time (drug effects, physiology)
• Substance P (analysis, drug effects)
• Touch
• Trigeminal Caudal Nucleus (drug effects, physiopathology)
• Vibrissae