Effects of buprenorphine on intracerebral collagenase-induced hematoma in Sprague-Dawley rats.

We evaluated the effects of buprenorphine (0.05 mg/kg intraperitoneally) after collagenase-induced intracerebral hemorrhage in Sprague-Dawley rats. Methods of evaluation included serum biochemistry, behavioral tests (neurologic exam and rotarod treadmill), and histopathology. Serum biochemistry parameters showed no change after surgery in controls and buprenorphine-treated animals. At 48 h after collagenase injections, the performance of treated rats on the rotarod treadmill test was not significantly different from that of untreated rats, but the neurologic exams of treated rats showed significantly improved performance. Although the volume of the hematoma was reduced with buprenorphine, the number of necrotic neurons in the penumbra was significantly increased. These data indicate that administration of buprenorphine led to neurologic and histopathologic differences in a rat model of intracerebral hemorrhage, and data from such studies should be interpreted carefully if an opioid analgesic is used to minimize pain.