Parallel stimulations of in vitro and in situ [35S]GTPgammaS binding by endomorphin 1 and DAMGO in mouse brains.
Metabotropic activities of endomorphin 1, a candidate for endogenous mu-opioid receptor ligands, were examined in comparison with the actions of [D-Ala2, N-Me-Phe4, Gly5ol]-enkephalin/DAMGO, a well-known synthetic mu-opioid agonist. Endomorphin 1 stimulated [35S]GTPgammaS binding to synaptic membranes from the mouse amygdala in a naloxone-reversible manner. DAMGO had the same effect in such preparations. In in situ [35S]GTP-gammaS binding experiments using brain sections, both endomorphin 1 and DAMGO similarly stimulated this binding in specific cellular locations throughout the brain regions. These findings strongly support the view that endomorphin 1 selectively acts on a mu-opioid receptor.
Kakizawa
K
K
Department of Molecular Pharmacology and Neuroscience, Nagasaki University, School of Pharmaceutical Sciences, Japan.
Shimohira
I
I
Sakurada
S
S
Fujimura
T
T
Murayama
K
K
Ueda
H
H
D000679:Amygdala / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D008024:Ligands; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology*; D017450:Receptors, Opioid, mu / Q000819:agonists*; D013570:Synaptic Membranes / Q000378:metabolism
D004745:Enkephalins; D008024:Ligands; D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C105293:endomorphin 1; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D019204:GTP-Binding Proteins