AJP - Endocrinology and Metabolism, Vol 261, Issue 2 E183-E189, Copyright © 1991 by American Physiological Society
Brain and atrial natriuretic peptides bind to common receptors in brain capillary endothelial cells
R. A. Gelfand, H. J. Frank, E. Levin and A. Pedram
Department of Medicine, Long Beach Veterans Administration, California.
The recent discovery of brain natriuretic peptides (BNP) that stimulates
natriuresis, diuresis, and vascular smooth muscle relaxation in a manner
similar to that of atrial natriuretic peptide (ANP) suggests the
possibility that these endocrine hormones function via some common
mechanism. Indirect evidence from several laboratories suggests that BNP
and ANP may bind to the same receptors. We examined whether ANP and BNP
bind to a common set of receptors in cultured bovine brain capillary
endothelial cells and in bovine aortic endothelial cells. Scatchard plot
analysis of binding data shows a similar dissociation constant (KD) of
approximately 0.3 nM and a maximal binding capacity (Bmax) of 50 fmol/mg
protein for both natriuretic peptides in brain capillary cells and 0.6 nM
and 80 fmol/mg protein, respectively, in the aortic endothelial cells.
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the affinity
cross-linked receptor-ligand complex shows a strongly labeled 65-kDa
receptor and a 125-kDa band that is likely to be a receptor of the
guanylate cyclase type. ANP and BNP cross compete equally for binding to
the two receptors identified on the gels. ANP and BNP also stimulate
guanosine 3', 5'-cyclic monophosphate production in these cells, consistent
with the presence of a functional guanylate cyclase-linked B receptor. We
conclude that ANP and BNP share common receptors in brain capillary and
aortic endothelial cells.
