Opioid peptides in Huntington's disease: alterations in prodynorphin and proenkephalin system.

The concentrations of dynorphin A1-8 and Met-enkephalin-Arg6-Gly7-Leu8 were measured in the basal ganglia of postmortem brains from patients with Huntington's disease (HD) and from control subjects. A significant reduction of dynorphin A1-8 concentration was found in caudate nucleus, putamen, external globus pallidus and substantia nigra of HD brains. Levels of Met-enkephalin-Arg6-Gly7-Leu8 were reduced in HD caudate nucleus, putamen, internal and external globus pallidus. These data indicate that both the prodynorphin and proenkephalin opioid peptide system are affected in the basal ganglia in HD.