Atrial natriuretic factor binding sites in rat area postrema: autoradiographic study.
Am J Physiol
; 263(4 Pt 2): R747-55, 1992 Oct.
Article
en En
| MEDLINE
| ID: mdl-1415784
ABSTRACT
The area postrema (AP) is a brain stem circumventricular organ implicated, among other functions, in central cardiovascular (CV) regulation. Competition binding analysis performed by quantitative in vitro autoradiography demonstrated specific, high-affinity (Kd, 0.32 +/- 0.11 nM), low-capacity (Bmax, 57.5 +/- 10.9 fmol/mg protein) atrial natriuretic factor (ANF) binding sites in the AP. C-ANF [des-(Gln116-Gly120)ANF-(Arg102-Cys121)-NH2] and ANF-(Phe106-Ile113)-NH2 (two ligands endowed with selectivity for the ANF-C receptor), as well as C-type natriuretic peptide (CNP), did not compete noticeably at pathophysiological concentrations for 125I-ANF binding. 125I-[Tyr0]CNP bound to the AP to a much lower extent than 125I-ANF. Electron microscopic autoradiography in vivo disclosed that 125I-ANF was preferentially bound to axon, dendrite, and astrocyte plasmalemma. These studies demonstrate that the AP contains natriuretic peptide binding sites with pharmacological characteristics of the ANF-A and ANF-B but not of the ANF-C receptor subtype. In the AP, ANF interacts with those sites resembling ANF-A receptors. Cellular localization of these binding sites may relate to their possible involvement in the centrally mediated salt and water regulation and/or CV effects of circulating ANF.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bulbo Raquídeo
/
Factor Natriurético Atrial
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol
Año:
1992
Tipo del documento:
Article
País de afiliación:
Canadá