title: Endothelin ET(B) receptors show different binding profiles in intact cells and cell membrane preparations.
abstract: We examined the affinity of endothelin-1, endothelin-3 and four endothelin receptor ligands, BQ788 (cis-2,6-dimethylpiperidinocarbonyl-gamma-methyl-Leu-D-Trp(1-CO 2CH3-D-Nle-ONa), SB-209670 ((+)-(1S,2R,3S)-3-(2-carboxymethoxy-4-methoxyphenyl)-1-(3,4-methylenedio xyphenyl)-5-(prop-1-yloxy)indane-2-carboxylic acid), IRL-1620 (succinyl-[Glu9,Ala11,15]endothelin-1(8-21)), and L-749329 (3',4'-methylenedioxy-1-(2-propyl-4-carboxyphenoxy)-N-(4-isopropyl -phenylsulfonyl)-benzene acetamide), for endothelin ET(B) receptors in human and rat heart cells. The affinities of these ligands showed good correlation between both types of living cells and between their membrane preparations (r = 0.861, P < 0.001), but less significant correlation between each of the living cells and its respective membrane preparation (r = 0.569, 0.02 < P < 0.05). These results suggest that there is no species difference in the affinities of these ligands and that destruction of the intact cell membrane structure may lead to changes in binding properties of the endothelin ET(B) receptor.
authors.affiliation: Shionogi Research Laboratories, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: F
authors.initials: F
authors.lastname: Tozawa
authors.forename: K
authors.initials: K
authors.lastname: Itazaki
authors.forename: S
authors.initials: S
authors.lastname: Mihara
authors.forename: M
authors.initials: M
authors.lastname: Fujimoto
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D019333:Endothelin-2 / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008024:Ligands; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin / Q000187:drug effects / Q000378:metabolism*
chemical_list: D019333:Endothelin-2; D007457:Iodine Radioisotopes; D008024:Ligands; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin