Atrial natriuretic peptide receptors and activation of guanylate cyclase in rat cardiac sarcolemma.
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.
Rugg
E L
EL
Department of Biology and Preclinical Medicine, University of St. Andrews, Fife, UK.
Aiton
J F
JF
Cramb
G
G
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
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