Specific atrial natriuretic peptide binding sites in rat cerebral capillaries.
We examined the specific rat 125I-alpha-rat atrial natriuretic peptide(1-28)[ANF-(99-126)] (125I-rANP) binding sites in the cerebral capillaries from the cerebral cortex of male adult Wistar rats. The binding of 125I-rANP at 37 degrees C was saturable and of high affinity with a Kd of approximately 100 pM and Bmax of 152 fmol/mg protein. Divalent cations, Mn2+ (2.2 mM) and Ca2+ (1.8 mM) potently inhibited the binding. The rank order for inhibition of the binding was rANP, alpha-human ANP and ANF-(101-126) greater than ANF-(103-126) and ANF-(103-125)"ANF-(103-123). These data on specific binding sites of ANP in cerebral capillaries suggest a possible role for ANP in the blood-brain permeability of water and electrolytes.
Niwa
M
M
Department of Pharmacology, Nagasaki University School of Medicine, Japan.
Ibaragi
M
M
Tsutsumi
K
K
Kurihara
M
M
Himeno
A
A
Mori
K
K
Ozaki
M
M
D000818:Animals; D001665:Binding Sites; D002196:Capillaries / Q000378:metabolism; D002413:Cations, Divalent / Q000494:pharmacology; D002540:Cerebral Cortex / Q000098:blood supply* / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013347:Subcellular Fractions
D002413:Cations, Divalent; D011956:Receptors, Cell Surface; D017461:Receptors, Atrial Natriuretic Factor