Kainic acid lesion of the striatum increases dopamine release but reduces 3-methoxytyramine level.

Kainic acid lesion of the striatum leads to the disruption of the striatonigral regulatory loop. Although microdialysis showed an increase in dopamine release, two days after kainic acid injection, 3-methoxytyramine levels are dramatically decreased. This suggests that the postsynaptic membrane-bound catechol-O-methyltransferase (COMT), but not the glial COMT, is responsible for the formation of measured 3-methoxytyramine.