Local enkephalins tonically modulate dopamine release in the striatum: a microdialysis study.

ABSTRACT

Kelatorphan, an inhibitor of the enkephalin-degrading enzymes, infused by microdialysis (10(-6) M) in the striatum of anaesthetized rats, significantly increased dopamine (DA) output but left dihydroxyphenylacetic acid and homovanillic acid extracellular levels unchanged. The local application of naltrexone (10(-6) M) prevented the effect of kelatorphan on DA release. These data indicate that local enkephalins tonically modulate DA release in rat striatum.