Buprenorphine Prevents Remifentanil-Enhanced Mechanical Allodynia in a Rat Inflammatory Pain Model

Purpose Remifentanil is a μ-receptor agonist known to cause pain hypersensitivity. Buprenorphine targets multiple opioid receptors and exhibits good anti-hyperalgesic characteristics. We investigated whether pre-treatment with buprenorphine could prevent13;13;
remifentanil-enhanced mechanical allodynia in an inflammatory pain model.13;13;
Methods Inflammatory pain was induced by subcutaneous carrageenan injection into the hind paw of rats. In experiment 1, rats were randomized to receive intravenous remifentanil（10 μg・kg^(-1)・min^(-1) or 30 μg・kg^(-1)・min^(-1)）or saline for 30 min. In experiment 2, buprenorphine（25 μg/kg）or saline was injected intravenously 10 min before remifentanil administration. Mechanical thresholds of hind paws were evaluated using von Frey filaments at 1 and 3h after carrageenan injection and daily thereafter for 7 days.13;13;
Results Intravenous infusion of remifentanil significantly enhanced bilateral mechanical allodynia induced by carrageenan. Pre-treatment with buprenorphine prevented remifentanil-enhanced bilateral mechanical allodynia significantly.13;13;
Conclusion Pre-treatment with buprenorphine effectively prevents remifentanil-enhanced mechanical allodynia in an inflammatory pain model.13;13;
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