A Rat Model of Full Thickness Thermal Injury Characterized by Thermal Hyperalgesia, Mechanical Allodynia, Pronociceptive Peptide Release and Tramadol Analgesia
Abstract
Opioid related side effects are problematic for burn patients. Dual mechanism therapeutics targeting opioid and non opioid mechanisms may have reduced side effects with similar analgesic efficacy. Ttramadol combines mu opioid receptor agonism with norepinephrine reuptake inhibition and has been effective in treating some types of pain. The effectiveness of tramadol in treating pain associated with burns is unclear. We hypothesized that tramdol is effective in reducing thermal injury evoked pain behaviors in a rat model. Rates were anesthetized and a 100 deg C metal probe was placed on the hind paw for 30 s to induce a full thickness thermal injury. A subset of rates was perfusion fixed and hind paw tissue and spinal cord collected for anatomical analysis. Rates received morphine (5 mg/kg i.p.), tramadol (10 30 mg/kg i.p.) or vehicle and latency to paw withdrawal from a noxious thermal or non noxious mechanical stimulus was recorded every 10 min over 70 min and again at 2 h. We report that pain behaviors developed within 48 h and peaked at 1 week paralleled by enhanced expression of pronociceptive neuropeptides in the spinal cord. Morphine and tramadol significantly attenuated hyperalgesia and allodynia while not significantly altering motor coordination/sedation. These data indicate dual mechanism therapeutics may be effective for treating pain associated with burns.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2014
- Accession Number
- ADA614724
Entities
People
- Dayna L Averitt
- Helen M. Arizpe
- John L. Clifford
- Joseph Novak
- Lawrence N. Petz
- Marcie Fowler
- Terry M. Slater
- Thomas H. Garza
Organizations
- United States Army Institute of Surgical Research