Buprenorphine potentiates L-DOPA-induced contralateral rotation in 6-hydroxydopamine-treated rats

Animals are commonly given opioid analgetics such as buprenorphine for post-operative pain management. In this study, the effect of the analgetic buprenorphine, a partial mu receptor agonist and kappa receptor antagonist, on L-DOPA-induced contralateral rotation was measured in 6-hydroxydopamine (6-OHDA) treated rats. Male Sprague-Dawley rats received dopamine-depleting brain lesions by infusion of 6-OHDA into the medial forebrain bundle. After the procedure, buprenorphine was administered (430 microg/kg, s.c.) to 17 of 54 animals. Three weeks after 6-OHDA treatment, animals were given benserazide HCI (25 mg/kg, i.p.) and L-DOPA (4 mg/kg, i.p.). Contralateral rotations were monitored for 2 h. Animals receiving buprenorphine had significantly higher rates of rotation as compared with non-buprenorphine-treated animals (P = 0.023). The results suggest that buprenorphine sensitizes animals to the effects of L-DOPA.