Effects of repeated administration of buprenorphine on ambulatory activity in mice

Effects of repeated administration of buprenorphine, given 5 times at intervals of 3-4 days, were investigated by ambulatory activity in mice. Buprenorphine (0.3 and 1 mg/kg sc) significantly increased the activity, and tolerance to the effect tended to be produced during the repeated administration schedule. The mice that experienced the repeated administration of buprenorphine exhibited an increased sensitivity to the ambulation-increasing effect of methamphetamine (2 mg/kg) in parallel with the doses of buprenorphine. However, no significant modification of the sensitivity to buprenorphine was produced in the mice that had experienced the repeated methamphetamine administration. Furthermore, the established reverse tolerance to methamphetamine was not significantly modified by the repeated treatment with buprenorphine (0.1, 0.3 and 1 mg/kg).