title: Specific receptors for atrial natriuretic factor (ANF) in cultured vascular smooth muscle cells of rat aorta.
abstract: Specific binding site for atrial natriuretic factor (ANF), a potent natriuretic and vasorelaxant polypeptide recently isolated from mammalian atria, was studied in cultured vascular smooth muscle cells (VSMC) of the rat aorta. Binding studies of 125I-labeled-synthetic alpha-human natriuretic peptide (alpha-hANP) revealed the presence of a non-interacting, single class of high affinity binding sites for alpha-hANP on VSMC in culture: the apparent dissociation constant (Kd) was approximately 1-2 X 10(-9)M and the number of maximal binding sites was approximately 200,000-300,000 sites/cell. A variety of vasoactive substances and other polypeptide hormones did not affect the binding of 125I-labeled-alpha-hANP to its binding sites. alpha-hANP significantly increased the concentrations of intracellular cyclic GMP in VSMC in a dose-dependent manner (3.2 X 10(-9)-1.6 X 10(-7)M). These data indicate that the specific receptor for ANF is present in VSMC and suggest that intracellular cyclic GMP may be involved in its vasorelaxant effect.
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D009320:Atrial Natriuretic Factor; D001667:Binding, Competitive; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D007700:Kinetics; D009124:Muscle Proteins / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D011956:Receptors, Cell Surface; C472610:atrial natriuretic peptide, rat; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP