Enkephalinergic Markers in Substantia Nigra and Caudate Nucleus from Parkinsonian Subjects

Abstract
Marked reductions in opiate receptor binding (−42%), “enkephalinase” activity (−39%), and Met5-enkephalin levels (−72%) accompanied the well-established dopamine depletion in the substantia nigra pars compacta of Parkinsonian subjects. In contrast, enkephalinergic markers were not significantly modified in caudate nucleus.