title: Atrial natriuretic peptide receptors and activation of guanylate cyclase in rat cardiac sarcolemma.
abstract: Two classes of atrial natriuretic peptide (ANP) receptors are present in purified sarcolemmal membrane fractions isolated from rat ventricle. Scatchard analysis using [125I]-ANP reveals high affinity (Kd approximately 10(-11) M) and low affinity (Kd approximately 10(-9) M) binding sites. Basal guanylate cyclase activities associated with these membrane fractions range from 3.2 +/- 1.3 pmol/min/mg protein in the presence of Mg2+ to 129 +/- 17 pmol/min/mg protein in the presence of Mn2+. Millimolar concentrations of adenosine triphosphate (ATP) potentiates Mg2+- but not Mn2+-supported activity. Binding of ANP to the low affinity site but not the high affinity site results in a maximum 2-fold activation of Mn2+- and up to 6-fold activation of Mg2+/ATP supported guanylate cyclase activities.
authors.affiliation: Department of Biology and Preclinical Medicine, University of St. Andrews, Fife, UK.
authors.forename: E L
authors.initials: EL
authors.lastname: Rugg
authors.forename: J F
authors.initials: JF
authors.lastname: Aiton
authors.forename: G
authors.initials: G
authors.lastname: Cramb
mesh_terms: D000227:Adenine Nucleotides / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000502:physiology*; D002413:Cations, Divalent; D004789:Enzyme Activation; D006020:Glycopeptides / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism*; D066298:In Vitro Techniques; D009206:Myocardium / Q000201:enzymology*; D051381:Rats; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000502:physiology*; D012508:Sarcolemma / Q000201:enzymology
chemical_list: D000227:Adenine Nucleotides; D002413:Cations, Divalent; D006020:Glycopeptides; D011956:Receptors, Cell Surface; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; C008890:phosphoramidon