The non-peptide neuropeptide Y Y1 receptor antagonist BIBP3226 blocks the [Leu31,Pro34]neuropeptide Y-induced modulation of alpha 2-adrenoceptors in the nucleus tractus solitarii of the rat.
The potential blockade of the neuropeptide Y (NPY) Y1 receptor agonist [Leu31,Pro34]NPY-induced modulation of the characteristics of alpha 2-adrenoceptor agonist [3H]p-aminoclonidine binding sites by a selective non-peptide NPY Y1 receptor antagonist BIBP3226, was studied in the nucleus tractus solitarii of the rat by means of quantitative receptor autoradiography. [Leu31,Pro34]NPY at a concentration of 10 nM significantly increased the Kd value of [3H]p-aminoclonidine binding sites in the nucleus tractus solitarii without influencing the Bmax, suggesting the existence of an antagonistic modulation by NPY Y1 receptors of alpha 2-adrenoceptors in the nucleus tractus solitarii. BIBP3226 at 100 nM fully blocked the [Leu31,Pro34]NPY-induced increase in Kd of the [3H]p-aminoclonidine binding sites. The present results therefore provide evidence, by use of a NPY Y1 receptor antagonist, for the existence of a NPY Y1/alpha 2 receptor interaction in the nucleus tractus solitarii.
Yang
S N
SN
Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
Finnman
U B
UB
Fuxe
K
K
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects*; D017476:Receptors, Neuropeptide Y / Q000037:antagonists & inhibitors*; D017552:Solitary Nucleus / Q000187:drug effects*
C092926:BIBP 3226; D018341:Receptors, Adrenergic, alpha-2; D017476:Receptors, Neuropeptide Y; D001120:Arginine