Autoradiographic localization of atrial and brain natriuretic peptide receptors in rat brain.
Displacement of bound 125I-labeled atrial natriuretic peptide-(1-28) [alpha 125I-ANP-(1-28)] by alpha-ANP-(5-28) and porcine brain natriuretic peptide (BNP) was used to map receptors common to these peptides in rat brain by in vitro autoradiography. alpha-125I-ANP bound reversibly to subfornical organ, area postrema, median preoptic, supraoptic and paraventricular nuclei, and arachnoid mater. Binding at these sites was displaced similarly by 1 microM unlabeled alpha-ANP, alpha-ANP-(5-28), and BNP. Binding dissociation constants in the subfornical organ and arachnoid were 4.40 +/- 1.15 and 3.99 +/- 0.86 nM, respectively, for alpha-ANP, and 2.41 +/- 1.11 and 2.23 +/- 1.06 nM, respectively, for BNP. alpha-125I-ANP also bound to choroid plexus. Here 1 microM unlabeled alpha-ANP displaced significantly more radioligand than did 1 microM BNP, and the concentration displacing 50% of bound radioligand was 2.23 +/- 0.78 nM for alpha-ANP and 1.51 +/- 0.67 nM for BNP. alpha-ANP-(5-28) also displaced alpha 125I-ANP at all sites with significantly greater affinity than did unlabeled alpha-ANP. alpha-125I-ANP was not displaced by completely unrelated peptides. Therefore, both atrial and brain natriuretic peptides may be high-affinity ligands at common receptors in some cerebral localities.
Brown
J
J
Physiological Laboratory, Cambridge, United Kingdom.
Czarnecki
A
A
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001345:Autoradiography; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013552:Swine
D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; C058930:brain natriuretic peptide receptor; D009320:Atrial Natriuretic Factor; C054538:atrial natriuretic factor (5-28); D017461:Receptors, Atrial Natriuretic Factor