NEUROTENSIN, SUBSTANCE-P, DELTA-OPIOID AND MU-OPIOID RECEPTORS ARE DECREASED BASAL GANGLIA OF PARKINSONS-DISEASE PATIENTS

The specific binding of [H-3]neurotensin, [H-3]substance P, [H-3]D-Ala (2)-D-Leu(5)-enkephalin (delta receptors) and [H-3]-Tyr-D-Ala-Gly-(NMe )Phe-Gly-ol (mu receptors) were studied in membrane preparations of ca udate nucleus, putamen, globus pallidus and substantia nigra from pati ents with Parkinson's disease and from age-matched controls. The densi ty of neurotensin receptors was decreased in globus pallidus (lateral and medial segments) in parkinsonian brain. Substance P receptors were reduced in the putamen (anterior and posterior) and in lateral globus pallidus in Parkinson's disease. There was a reduction in the density of opioid receptors in posterior putamen and in mu receptors in cauda te nucleus and putamen (anterior and posterior). No differences in neu ropeptide receptor binding were observed in substantia nigra from park insonian brains compared with control subjects. The reductions in neur opeptide receptor density were less marked than the decrease in caudat e and putamen content of dopamine and its metabolites. This suggests t hat neuropeptide receptors are only partially localized to striatal do pamine terminals.