Neuropeptide Y receptor binding sites in rat brain: differential autoradiographic localizations with sup 125 I-peptide YY and sup 125 I-neuropeptide Y imply receptor heterogeneity

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Journal of Neuroscience; (USA)

OSTI ID:5413044

Lynch, D R; Walker, M W; Miller, R J; Snyder, S H ^[1]

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1. Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA)

Neuropeptide Y (NPY) receptor binding sites have been localized in the rat brain by in vitro autoradiography using picomolar concentrations of both 125I-NPY and 125I-peptide YY (PYY) and new evidence provided for differentially localized receptor subtypes. Equilibrium binding studies using membranes indicate that rat brain contains a small population of high-affinity binding sites and a large population of moderate-affinity binding sites. 125I-PYY (10 pM) is selective for high-affinity binding sites (KD = 23 pM), whereas 10 pM 125I-NPY labels both high- and moderate-affinity sites (KD = 54 pM and 920 pM). The peptide specificity and affinity of these ligands in autoradiographic experiments match those seen in homogenates. Binding sites for 125I-PYY are most concentrated in the lateral septum, stratum oriens, and radiatum of the hippocampus, amygdala, piriform cortex, entorhinal cortex, several thalamic nuclei, including the reuniens and lateral posterior nuclei, and substantia nigra, pars compacta, and pars lateralis. In the brain stem, 125I-PYY sites are densest in a variety of nuclei on the floor of the fourth ventricle, including the pontine central grey, the supragenual nucleus, and the area postrema. 125I-NPY binding sites are found in similar areas, but relative levels of NPY binding and PYY binding differ regionally, suggesting differences in sites labeled by the two ligands. These receptor localizations resemble the distribution of endogenous NPY in some areas, but others, such as the hypothalamus, contain NPY immunoreactivity but few binding sites.

• OSTI ID: 5413044
• Journal Information: Journal of Neuroscience; (USA), Journal Name: Journal of Neuroscience; (USA) Vol. 9:8; ISSN JNRSD; ISSN 0270-6474
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOLOGICAL LOCALIZATION
BODY
BRAIN
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEINS
RADIOISOTOPES
RATS
RECEPTORS
RODENTS
TISSUE DISTRIBUTION
VERTEBRATES