Extrahypothalamic vasopressin is unchanged in Parkinson's disease and Huntington's disease

Vasopressin immunoreactivity was measured post-mortem in the locus coeruleus and substantia nigra of 16 cases of Parkinson's disease and multisystem atrophy, 10 cases of Huntington's chorea and 28 normal controls. Amounts of vasopressin did not differ significantly (P greater than 0.05) between the 3 groups. Immunohistochemistry demonstrated vasopressin within nerve terminals. These data are consistent with an extrinsic vasopressin system in the human locus coeruleus and substantia nigra.