alpha-neoendorphin and Parkinson-Disease

A motor disorder similar to idiopathic Parkinson's Disease develops in rhesus monkeys after several daily repeated doses of N-methyl-4-phenyl, 1,2,3,6-tetrahydropyridine (MPTP). The concentrations of peptides derived from proenkephalin A, proenkephalin B, substance P and somatostatin were measured by specific radioimmunoassays in the basal ganglia of MPTP-treated monkeys. In MPTP-treated monkeys, dynorphin B concentration was reduced in the caudate. In the putamen, the concentrations of peptides derived from both proenkephalin A and proenkephalin B were decreased. In the globus pallidus, the concentrations of all opioid peptides tend to be increased, reaching significance only for alpha-neo-endorphin. In the substantia nigra, only Met-enkephalin concentration was reduced, while other peptides derived from either proenkephalin A or proenkephalin B were not changed. Substance P and somatostatin were not changed in any brain area examined. Some of the symptoms associated with Parkinson's Disease may be related to altered activity of endogenous opiates in basal ganglia.

Topics: Animals; Basal Ganglia; Dynorphins; Endorphins; Enkephalin, Leucine; Enkephalin, Methionine; Female; Macaca mulatta; Male; Nucleus Accumbens; Parkinson Disease; Protein Precursors; Substantia Nigra