title: High and low affinity binding sites for endothelin on cultured rat glomerular mesangial cells.
abstract: Endothelin contracts glomerular mesangial cells, thereby influencing glomerular size and filtration rate. Here, we demonstrate the presence of two ET-specific binding sites on cultured rat mesangial cells with Kds of 0.76 and 44.70 nM, and maximal binding capacity (Bmax) values of 6.78 x 10(2) and 27.60 x 10(2) binding sites/cell, respectively. Binding of [125I]-ET was maximal at 120 min at 4 degrees C, stable for the subsequent 60 min, and selective. No competition for binding was observed with greater than 1000-fold concentrations of atrial natriuretic peptide, angiotensin II, arginine vasopressin, nicardipine, or nifedipine. The presence of specific receptors for ET on glomerular mesangial cells suggests a major role for this peptide in the regulation of glomerular filtration rate.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2372.
authors.forename: K F
authors.initials: KF
authors.lastname: Badr
authors.forename: K A
authors.initials: KA
authors.lastname: Munger
authors.forename: M
authors.initials: M
authors.lastname: Sugiura
authors.forename: R M
authors.initials: RM
authors.lastname: Snajdar
authors.forename: M
authors.initials: M
authors.lastname: Schwartzberg
authors.forename: T
authors.initials: T
authors.lastname: Inagami
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D016232:Endothelins; D005920:Glomerular Mesangium / Q000378:metabolism*; D007700:Kinetics; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin
chemical_list: D016232:Endothelins; D010455:Peptides; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin