MK-801 fails to modify the effect of methamphetamine on dopamine release in the rat striatum.

The effect of MK-801 at a dose of 0.5 mg kg-1, i.p., on methamphetamine-induced (MAP; 4 mg kg-1, i.p.) dopamine (DA) release was examined in the striatum of freely moving rats using an in-vivo microdialysis method. Combined treatment of MK-801 with MAP did not modify the MAP-induced increase in extracellular DA levels or the decrease in 3,4-dihydroxyphenylacetic acid levels. These findings suggest that MK-801 fails to modify the acute effect of MAP on DA release in the striatum. The blocking effect of MK-801 on the development of MAP-induced behavioral sensitization is unlikely to be mediated by DA neurons.