Premium
Characterization of atrial natriuretic peptide receptors in brain microvessel endothelial cells
Author(s) -
Whitson Peggy A.,
Huls M. Helen,
Sams Clarence F.
Publication year - 1991
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041460107
Subject(s) - atrial natriuretic peptide , receptor , medicine , cyclic guanosine monophosphate , endocrinology , npr1 , chemistry , microvessel , brain natriuretic peptide , peptide hormone , guanosine , npr2 , dissociation constant , natriuretic peptide , biology , biochemistry , angiogenesis , heart failure , nitric oxide
Atrial natriuretic peptide (ANP) binding and ANP‐induced increases in cyclic guanosine monophosphate (cGMP) levels have been observed in brain microvessels (Chabrier et al., 1987; Steardo and Nathanson, 1987), suggesting that this fluid‐regulating hormone may play a role in the fluid homeostasis of the brain. This study was initiated to characterize the ANP receptors in primary cultures of brain microvessel endothelial cells (BMECs). The apparent equilibrium dissociation constant, Kd, for ANP increased from 0.25 nM to 2.5 nM, and the number of ANP binding sites as determined by Scatchard analysis increased from 7,100 to 170,000 sites/cell between 2 and 10 days of culture following monolayer formation. Time‐ and concentration‐dependent studies on the stimulation of cGMP levels by ANP indicated that guanylate cyclase‐linked ANP receptors were present in BMECs. The relative abilities of ANP, brain natriuretic peptide (BNP), and a truncated analog of ANP containing amino acids 5–27 (ANP 5–27) to modulate the accumulation of cGMP was found to be ANP >BNP ≫ ANP 5–27. Affinity cross‐linking with disuccinimidyl suberate and radiolabeled ANP followed by gel electrophoresis under reducing conditions demonstrated a single band corresponding to the 60–70 kD receptor, indicating the presence of the nonguanylate cyclase‐linked ANP receptor. Radiolabeled ANP binding was examined in the presence of various concentrations of either ANP, BNP, or ANP 5–27 and suggested that a large proportion of the ANP receptors present in blood‐brain barrier endothelial cells bind all of these ligands similarly. These data indicate both guanylate cyclase linked and nonguanylate cyclase linked receptors are present on BMECs and that a higher proportion of the nonguanylate cyclase linked receptors is expressed. This in vitro culture system may provide a valuable tool for the examination of ANP receptor expression and function in blood‐brain barrier endothelial cells.