Distribution of neuropeptide FF (FLFQPQRFamide) receptors in the adult rat spinal cord: effects of dorsal rhizotomy and neonatal capsaicin.
Neuroscience
; 68(4): 1229-35, 1995 Oct.
Article
em En
| MEDLINE
| ID: mdl-8544996
ABSTRACT
By using quantitative autoradiography and highly selective iodinated ligands, we quantified modifications in neuropeptide FF binding sites in the superficial layers (laminae I and II) of the cervical (C6-C8 segments) and lumbar (L3-L5 segments) enlargements in two models (i) rats neonatally treated with capsaicin; (ii) rat submitted 15 days before to unilateral dorsal rhizotomies. We comparatively analysed the distribution of mu-opioid binding sites in the same animals. We have shown that the [125I]YLFQPQRFamide (neuropeptide FF sites) labelling is not significantly modified following selective damage of fine afferent fibres by neonatal capsaicin treatment. In the cervical and lumbar enlargements, capsaicin-treated/control binding ratios for [125I]YLFQPQRFamide were 0.90 and 0.86, respectively. While unilateral dorsal rhizotomy induced a drastic decrease in [125I]FK-33-824 labelling in the side ipsilateral to the lesion as compared to the intact side of (yielding ratios of 0.29 and 0.31 for cervical and lumbar levels, respectively), [125I]YLFQPQRFamide labelling was not significantly modified, yielding ratios of 0.98 and 0.91 for cervical and lumbar levels, respectively. These data suggest that, in contrast with a majority of mu-opioid receptors, neuropeptide FF receptors are not located on fine primary afferent fibers carrying nociceptive information from the fore- or hindlimb in the rat. This preferential postsynaptic localization, together with the reported "morphine modulating" action of this peptide, support the proposal of a role for neuropeptide FF in intraspinal modulation of nociceptive input.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Medula Espinal
/
Capsaicina
/
Receptores de Neuropeptídeos
/
Rizotomia
/
Animais Recém-Nascidos
Limite:
Animals
Idioma:
En
Revista:
Neuroscience
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
França