Peripheral anti-hyperalgesia by oxcarbazepine: involvement of adenosine A(1) receptors

In this study we determined whether oxcarbazepine (OXC) could produce local peripheral antinociceptive effects in a rat model of inflammatory hyperalgesia, and whether adenosine receptors were involved. When coadministered with the pro-inflammatory compound concanavalin A, OXC (1000-3000 nmol/paw) caused a significant dose- and time-dependent anti-hyperalgesia. Caffeine (1000-1500 nmol/paw), a nonselective adenosine receptor antagonist, as well as 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (10-30 nmol/paw), a selective A, receptor antagonist, coadministered with OXC, significantly depressed its anti-hyperalgesic effect. Drugs injected into the contralateral hind paw did not produce significant effects. These results indicate that OXC produces local peripheral anti-hyperalgesic effects, which is mediated via peripheral A, receptors