Therapeutic effects of different doses of peroperative intravenous dexmedetomidine for postoperative incision pain in rats

Abstract

It is essential to minimize postoperative pain immediately after an operation. We compared the effects of different doses of preoperative intravenous dexmedetomidine (DMED) on treating postoperative incision pain in rats. Forty healthy, male, and clean-grade Sprague-Dawley rats were randomly divided into five groups: group C, group B, group D1, group D2, and group D3. The rat hindlimb incision pain model was implemented. The cumulative pain score of each group was determined at two h after surgery. Western blotting was used to determine the spinal cord expression of PKC γ, and high-performance liquid chromatography was used to determine spinal cord glutamate levels. Compared with group C, group B had a significantly greater cumulative pain score and greater spinal cord levels of PKCγ and glutamate. There were significantly lower pain scores and levels of PKCγ and glutamate in groups D2 and D3 than in group D1. Perioperative DMED reduced the release of glutamate and inhibited the expression of PKCγ in the rat spinal cord and these changes correlated with reduced postoperative pain. The treatment effect was most evident at the highest tested dose of DMED (1 µg/kg).