Autoradiographic distribution of tachykinin NK2 binding sites in the rat brain:: Comparison with NK1 and NK3 binding sites
Autoradiographic distribution of tachykinin NK2 binding sites in the rat brain:: Comparison with NK1 and NK3 binding sites
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DOI：
10.1016/s0306-4522(02)00748-0
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发表时间：
2003-01-01
期刊：
影响因子：
3.3
通讯作者：
Beaujouan, JC
中科院分区：
文献类型：
--
作者：
Saffroy, M;Torrens, Y;Beaujouan, JC
The autoradiographic distribution of tachykinin NK2 binding sites was determined in the adult rat brain using [I-125]neurokinin A in the presence of either senktide (NK3 agonist) and [Pro(9)]substance P (NK1 agonist) or senktide and SIR 140333 (NK1 antagonist). Indeed, this radioligand labels two subtypes of NK1 binding sites (which present a high affinity not only for SP but also for neurokinin A, neuropeptide K and neuropeptide gamma) as well as NK3 binding sites. The distribution of NK2 binding sites was also compared with those of NK1 and NK3 binding sites, these sites being labeled with [I-125]Bolton and Hunter substance P and [I-125]Bolton and Hunter eledoisin, respectively. In agreement with our results obtained with membranes from various brain structures, NK2-sensitive [I-125]neurokinin A labeling was mainly observed in few structures including the dorsal and ventral hippocampus, the septum, the thalamus and the prefrontal cortex. The density of NK2 binding sites was weak when compared with those of NK1 and NK3 binding sites. Marked differences were observed in the distributions of NK1, NK2 and NK3 binding sites. These results are discussed taking into consideration differences or similarities between the distributions of NK2-sensitive [I-125]neurokinin A binding sites and of their endogenous ligands (neurokinin A, neuropeptide K and neuropeptide gamma) but also local NK2 agonist responses blocked by NK2 antagonists. Insights on the roles of endogenous tachykinins in several brain functions are also discussed on the basis of the respective distributions of different neurokinin binding sites. (C) 2003 IBRO. Published by Elsevier Science Ltd. All rights reserved.
