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Autoradiographic distribution of [ 125 I]Leu 31 ,Pro 34 ]PYY and [ 125 I]PYY 3–36 binding sites in the rat brain evaluated with two newly developed Y 1 and Y 2 receptor radioligands
Author(s) -
Dumont Yvan,
Fournier Alain,
StPierre Serge,
Quirion Rémi
Publication year - 1996
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/(sici)1098-2396(199602)22:2<139::aid-syn7>3.0.co;2-e
Subject(s) - olfactory tubercle , anterior olfactory nucleus , piriform cortex , stria terminalis , dorsal raphe nucleus , olfactory bulb , septal nuclei , hippocampus , chemistry , nucleus , medicine , endocrinology , pyramidal cell , hippocampal formation , biology , central nervous system , receptor , neuroscience , biochemistry , serotonin , serotonergic
The peptide YY derivatives [Leu 31 ,Pro 34 ]PYY and PYY 3–36 are highly selective Y 1 and Y 2 agonists, devoid of activity on the Y 3 receptor subtype [Dumont et al. (1994) Molec. Brain Res., 26:3220–3324]. These selective ligands were iodinated and used to evaluate the respective quantitative autoradiographic distribution of the Y 1 and Y 2 receptor subtypes in the rat brain, excluding a potential contamination from Y 3 receptor. Specific [ 125 I][Leu 31 ,Pro 34 ]PYY (Y 1 ), and [ 125 I]PYY 3–36 (Y 2 ) binding sites are detected in various brain regions, but each showed a differential distribution profile. Y 1 /[ 125 I][Leu 31 ,Pro 34 ]PYY sites are especially concentrated in superficial layers of the cortex, the olfactory tubercle, islands of Calleja, tenia tecta, molecular layer of the dentate gyrus, several thalamic nuclei, and the posterior part of the medial mammaliary nucleus. These areas generally contained only low densities of Y 2 /[ 125 I]PYY 3–36 binding sites. In contrast, [ 125 I]PYY 3–36 binding is most abundant in multiple other regions including the lateral septum, piriform cortex, triangular septal nucleus, bed nucleus of the stria terminalis, oriens layer and stratum radiatum of the dorsal hippocampus, ventral tegmental area, substantia nigra, dorsal raphe nucleus, and the granular cell layer of the cerebellum. Few areas of the rat brain contained significant amounts of both [ 125 I][Leu 31 ,Pro 34 ]‐PYY and [ 125 I]PYY 3–36 binding sites such as the anterior olfactory nuclei, oriens layer and stratum radiatum of the ventral hippocampus, nucleus tractus solitarius, area postrema, and inferior olive. Taken together, these results and the use of two selective radioligands demonstrate further the discrete, differential distribution of the Y 1 and Y 2 receptor subtypes in the rat brain. © 1996 Wiley‐Liss, Inc.