title: Parallel alterations in Met-enkephalin and substance P levels in medial globus pallidus in Parkinson's disease patients.
abstract: Met-enkephalin (Met-enk) and substance P (SP) were measured by a combined high-performance liquid chromatography/radioimmunoanalysis method in medial (GPM) and lateral globus pallidus (GPL) from controls and from Parkinson's disease (PD) patients. All patients showed a similar marked (> 90%) reduction in dopamine (DA) levels in putamen compared with controls. However, based on DA levels in the caudate nucleus, two subgroups of PD patients were differentiated. In patients with > 80% decrease in caudate nucleus DA content, there was a three-fold increase in both Met-enk and SP levels in GPM. In contrast, in patients showing an approximately 50% reduction in DA content in caudate, levels of both peptides were markedly reduced (approximately 80%). Met-enk and SP levels in GPL were unchanged in PD. These results suggest that neurons containing Met-enk and SP projecting to GPM adapt according to the extent of degeneration in the substantia nigra in PD.
authors.affiliation: Department of Neuropharmacology, Cajal Institute, CSIC, Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: de Ceballos
authors.forename: A
authors.initials: A
authors.lastname: Fernandez
authors.forename: P
authors.initials: P
authors.lastname: Jenner
authors.forename: C D
authors.initials: CD
authors.lastname: Marsden
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000032:analysis; D004744:Enkephalin, Methionine / Q000032:analysis*; D005260:Female; D005917:Globus Pallidus / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism*; D011863:Radioimmunoassay; D012016:Reference Values; D013373:Substance P / Q000032:analysis*
chemical_list: D013373:Substance P; D004744:Enkephalin, Methionine; D004298:Dopamine