Binding of atrial and brain natriuretic peptides in brains of hypertensive rats.
Displacement of bound [125I]alpha-atrial natriuretic peptide (alpha-ANP) by brain natriuretic peptide (BNP) was used to map receptors common to both peptides in rat brain by in vitro autoradiography. Both spontaneously hypertensive rats (SHR) and the normotensive Wistar-Kyoto control strain (WKY) were studied. In both strains, [125I]alpha-ANP bound densely to subfornical organ, choroid plexus and arachnoid mater. Binding at these sites in either strain was displaced similarly by 1 microM unlabelled alpha-ANP or BNP. However, no [125I]alpha-ANP was displaced by peptides unrelated to alpha-ANP or BNP. In WKY, both alpha-ANP and BNP competed with similarly high affinities for binding sites occupied by [125I]alpha-ANP. This was also true for SHR. However, SHR showed a substantial reduction in the maximum number of binding sites in the subfornical organ and choroid plexus which were competed for by the peptides. Therefore, BNP may be a significant high affinity ligand for brain receptors previously thought specific for atrial natriuretic peptides, including receptors which vary between WKY and SHR.
Brown
J
J
Physiological Laboratory, Cambridge, U.K.
Czarnecki
A
A
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D006973:Hypertension / Q000378:metabolism*; D008297:Male; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR / Q000378:metabolism*; D011919:Rats, Inbred Strains / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor