Open AccessGalanin/α2-adrenoceptor interactions in telencephalic and diencephalic regions of the rat
Author(s) -
Zaida Dı́az-Cabiale,
José Ángel Narváez,
Maria Garcia-Coronel,
Kjell Fuxé
Publication year - 2001
Publication title -
neuroreport/neuroreport
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.607
H-Index - 188
eISSN - 1473-558X
pISSN - 0959-4965
DOI - 10.1097/00001756-200101220-00038
Subject(s) - galanin , endocrinology , medicine , hypothalamus , amygdala , agonist , neuropeptide , radioligand , chemistry , galanin receptor , antagonist , receptor , biology
The aim of this study was to evaluate whether galanin could affect central alpha2-adrenoceptors in telencephalic and diencephalic regions in the rat using quantitative receptor autoradiography with the alpha2 agonist radioligand [3H]p-aminoclonidine. Galanin 1 nM significantly and substantially increased the Kd value of the [3H]p-aminoclonidine binding sites in the medial hypothalamus and amygdala by 86% (p < 0.01) and 73% (p < 0.05) respectively. The Bmax value was only significantly increased with 3 nM galanin in the amygdala and the medial hypothalamus (both p < 0.05). The antagonist M35 counteracted the increase of the Kd values of the alpha2-adrenoceptor agonist binding sites produced by galanin 1 nM in the amygdala and the medial hypothalamus (both p < 0.001). These findings suggest the existence of an antagonistic galanin/alpha2 adrenoceptor interaction in the medial hypothalamus and amygdala that may be of relevance for alpha2-adrenoceptor-regulated neuroendocrine functions and food intake.