Huntington's disease: changes in tachykinin content in postmortem brains

Substance P, neurokinin A, neuropeptide K, and neurokinin B were measured in both control (neurologically normal) and Huntington's disease brains obtained post mortem. All four peptides were significantly reduced in the substantia nigra of Huntington's disease patients compared with the control group. No differences were observed in frontal or temporal cortex except that neuropeptide K was significantly reduced in the frontal cortex of Huntington's disease cases. Correlation of the cell loss observed in the striatum and the tachykinin depletions detected in the substantia nigra in the Huntington's disease brains showed that the degree of cell loss agreed well with the extent of tachykinin depletion. Results of double-staining immunocytochemistry were consistent with the coexistence of substance P and neurokinin A in the substantia nigra of control brains and showed a marked depletion of immunoreactivity to both in Huntington's disease brains.