Comparison of [125I]-bolton-hunter substance P binding in young and aged rat spinal cord.

Autor: Maguire CM; Department of Biomedical Science, University of Tasmania at Launceston, P.O. Box 1214, Launceston, Tasmania 7250, Australia., Geraghty DP
Jazyk: angličtina
Zdroj: Brain research [Brain Res] 1998 Mar 09; Vol. 786 (1-2), pp. 263-6.
DOI: 10.1016/s0006-8993(97)01463-7
Abstrakt: Binding of [125I]-labeled Bolton-Hunter substance P ([125I]-BHSP) to NK1 receptors was investigated in the spinal cord of young (3-4 month) and aged (14-16 month) rats. In homogenates of whole spinal cord, the affinity (equilibrium dissociation constant, approximately 210 pM) and maximum density of [125I]-BHSP binding sites ( approximately 0.25 fmol/mg wet weight) were similar for young and aged rats. Autoradiographic studies revealed a similar distribution of [125I]-BHSP sites in both young and old rats at all spinal levels. Intense binding was observed in the superficial dorsal horn (laminae I-III), grey commissure (lamina X) and thoracic intermediolateral cell column (IML) with lower levels of binding in the deeper dorsal horn (laminae IV-VI) and ventral horn (laminae VII-IX). However, the density of [125I]-BHSP sites was significantly (P<0.05) lower in lamina X of lumbar sections of aged rats compared with young controls. These studies suggest that ageing is associated with a selective loss of NK1 receptors in lamina X of the lumbar spinal cord, although the affinity of NK1 receptors in aged rats is unchanged.
(Copyright 1998 Elsevier Science B.V.)
Databáze: MEDLINE
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