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Effects of atrial and brain natriuretic peptides upon cyclic GMP levels, potassium transport, and receptor binding in rat astrocytes
Author(s) -
Beaumont K.,
Tan P. K.
Publication year - 1990
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490250215
Subject(s) - atrial natriuretic peptide , medicine , receptor , endocrinology , bumetanide , astrocyte , npr1 , chemistry , brain natriuretic peptide , natriuretic peptide , npr2 , peptide , peptide hormone , cotransporter , biology , biochemistry , central nervous system , sodium , heart failure , organic chemistry
The ability of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) to alter cyclic GMP levels and NaKCl cotransport in rat neocortical astrocytes was determined. At concentrations of 10 −9 –10 − M, rat ANP 99–126 (rANF), rat ANP 102–126 (auriculin B), and rat ANP 103–126 (atriopeptin III) stimulated 6‐ to 100‐fold increases in cyclic GMP levels. Porcine BNP (pBNP) and rat BNP (rBNP) were 20%–90% as effective as rANF over most of this concentration range, although 10 −6 M pBNP produced a greater effect than rANF. NaKCl cotransport as measured by bumetanide‐sensitive 86 Rb + influx was not altered by exposure of astrocytes to 10 −6 M rANF, pBNP, or rBNP. Both pBNP and rBNP, as well as rat ANP 103–123 (atriopeptin I) and des[gln 18 , ser 19 , gly 20 , leu 21 , gly 22 ] ANF 4− ‐NH 2 (C‐ANF 4–23 ) strongly competed for specific 125 I‐rANF binding sites in astrocyte membranes with affinities ranging from 0.03 to 0.4 nM, suggesting that virtually all binding sites measured at subnanomolar concentrations of 125 I‐rANF were of the ANP‐C (ANF‐R 2 ) receptor subtype. These receptors are thought to serve a clearance function (Maack et al.: Science 238:675–678, 1987) and may be linked to a guanylate cyclase activity that is chemically and pharmacologically distinct from that coupled to ANP‐A (ANF‐R 1 ) receptors (Féthiere et al.: Mol Pharmacol 35:584–592, 1989). ANP receptors on astrocytes may function in limiting the access of ANP and BNP to neurons involved in body fluid and cardiovascular regulation.