Binding of gold-protein ligand complexes to neurokinin receptors. visualization with the electron microscope on pig coronary artery and rat portal vein

Article Article scientifique Article Binding of gold-protein ligand complexes to neurokinin receptors. visualization with the electron microscope on pig coronary artery and rat portal vein eng 1999 author Cathieni M M author Taban C H author Sors Patrick 26105 author Mastrangelo Domenico 29705 59-67 10.1159/000025626 10050074 1018-1172 Active neurokinin (NK) receptors were visualized with 5-nm colloidal gold-protein-substance P (GPSP) and -senktide (GPSenk) complexes on vascular tissues. Electron micrographs of pig coronary strips incubated with GPSP showed gold particles either bound to the plasmalemma or inside intracytoplasmic vesicles of endothelial cells. Preincubation with SP or the NK1 receptor antagonist L-703606 prevented GPSP marking. No gold particles were seen after incubation with GPSenk. On coronary strips in vitro, which had been precontracted with U46619, GPSP induced relaxations similar to those produced by equimolar concentrations of SP, both relaxations being inhibited by L-703606. Analogous to senktide, GPSenk was totally inactive on arterial strips. Incubation of rat portal veins with GPSenk showed gold particles bound to the plasmalemma or inside intracytoplasmic vesicles of smooth muscle cells. Preincubation with senktide or the NK3 receptor antagonist R-820 prevented GPSenk marking. On portal veins in vitro GPSenk induced contractions similar to those induced by equimolar concentrations of senktide or NKB; these effects were inhibited by R-820. Our results show that colloidal gold-protein complexes present biological activity and selectivity similar to those of their respective native ligand and detect the presence of active receptors; in addition, they suggest the presence of NK-receptor-mediated endocytosis in endothelial cells of coronary artery and in smooth muscle cells of the portal vein. Animals Coronary Vessels Endothelium, Vascular/metabolism Gold Colloid In Vitro Techniques Ligands Male Microscopy, Electron Muscle Contraction/drug effects Muscle Relaxation/drug effects Muscle, Smooth, Vascular/metabolism Peptide Fragments/metabolism/pharmacology Portal Vein Rats Rats, Sprague-Dawley Receptors, Neurokinin-1/metabolism Receptors, Neurokinin-2/metabolism Substance P/analogs & derivatives/metabolism/pharmacology Swine Dewey 617 57 Département de chirurgie 222 false 81 Groupe Iselin Christophe (urologie) 106 Journal of vascular research 36 1 3567280e-c4b7-4489-a259-a6c77bc0c0d3 Article (Published version) Restricted document.pdf 503864 application/pdf restrictedAccess Faculté de médecine / Section de médecine clinique / Département de chirurgie

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Binding of gold-protein ligand complexes to neurokinin receptors. visualization with the electron microscope on pig coronary artery and rat portal vein	Journal of vascular research			1999	539	0

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Sors, Patrick