title: Regulation of atrial natriuretic factor receptors by angiotensin II in rat vascular smooth muscle cells.
abstract: Atrial natriuretic factor (ANF) is actively involved in the control of blood pressure and fluid homeostasis as a physiological antagonist of the renin-angiotensin system. To evaluate a possible interaction between ANF and angiotensin II (Ang-II) receptors, we investigated the effect of long term pretreatment (18 h) of rat cultured vascular smooth muscle cells with Ang-II. Binding of 125I-labeled ANF and cyclic GMP production induced by ANF were measured. After preincubation of the cells with Ang-II (1, 10, and 100 nM), the number of ANF binding sites (Bmax) was decreased by 30, 59, and 71%, respectively, with a slight decrease of the Kd values. Sar1-Ile8-Ang-II (100 nM), a specific Ang-II receptor antagonist, totally inhibited the down-regulation induced by Ang-II (10 nM). Moreover, the regulatory effect of Ang-II on ANF receptors appeared more slowly as compared to ANF homologous receptor regulation. Ang-II pretreatment did not desensitize but increased cyclic GMP production elicited by ANF, implying that only the number of non-guanylate cyclase-coupled receptors was affected. These findings, which were not observed with 100 nM of epinephrine, norepinephrine, histamine, serotonin, and Arg-vasopressin, demonstrate a specific and functional link between ANF and Ang-II receptors. This study also shows that the regulation of ANF receptors is heterogeneous, providing new evidence of multiple classes of ANF receptors.
authors.affiliation: Institut Henri Beaufour Research Laboratories, Les Ulis, France.
authors.forename: P E
authors.initials: PE
authors.lastname: Chabrier
authors.forename: P
authors.initials: P
authors.lastname: Roubert
authors.forename: M O
authors.initials: MO
authors.lastname: Lonchampt
authors.forename: P
authors.initials: P
authors.lastname: Plas
authors.forename: P
authors.initials: P
authors.lastname: Braquet
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D009320:Atrial Natriuretic Factor; D007700:Kinetics; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011956:Receptors, Cell Surface; C472610:atrial natriuretic peptide, rat; D000804:Angiotensin II; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor