A rat model of full thickness thermal injury characterized by thermal hyperalgesia, mechanical allodynia, pronociceptive peptide release and tramadol analgesia.
Burns
; 40(4): 759-71, 2014 Jun.
Article
in En
| MEDLINE
| ID: mdl-24290856
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. Tramadol 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 tramadol is effective in reducing thermal injury-evoked pain behaviors in a rat model. Rats were anesthetized and a 100°C metal probe was placed on the hindpaw for 30 s to induce a full thickness thermal injury. A subset of rats was perfusion fixed and hindpaw tissue and spinal cord collected for anatomical analysis. Rats 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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Spinal Cord
/
Tramadol
/
Burns
/
Substance P
/
Calcitonin Gene-Related Peptide
/
Nociception
/
Hyperalgesia
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Analgesics, Opioid
/
Morphine
Type of study:
Etiology_studies
Limits:
Animals
Language:
En
Journal:
Burns
Journal subject:
TRAUMATOLOGIA
Year:
2014
Document type:
Article
Affiliation country: