title: Effect of alpha- and beta-adrenergic stimulation on atrial natriuretic peptide release in vitro.
abstract: The role of intracellular signals in the regulation of atrial natriuretic peptide (ANP) release was studied using the isolated left and right atria from a rat. The atria were perfused with Tyrode's solution, equilibrated with 95% O2-5% CO2 at 37 degrees C with a constant flow of 0.5 ml/min. Addition of epinephrine (10(-6) M), an alpha- and beta-agonist, to the perfusate induced the biphasic release of ANP from the right atrium without effect on the left. The initial peak (19.2 +/- 2.6 pg.min-1.ml-1) occurs 2-4 min after the administration of epinephrine, which lasted 4-6 min and returned to base line (10.4 +/- 1.1 pg.min-1.mg-1). The second peak (16.5 +/- 2.0 pg.min-1.ml-1) appeared 30-35 min after epinephrine administration and was sustained for 100 min, at which time the experiment was terminated. The first peak was stimulated by isoproterenol (10(-6) M), a beta-agonist, and blunted by propranolol (10(-6) M), a beta-antagonist. The second peak appeared following methoxamine (10(-6) M), an alpha-agonist, and could be suppressed by phentolamine (10(-6) M), an alpha-antagonist. These studies indirectly suggest that the adenosine 3',5'-cyclic monophosphate system and the inositol triphosphate system are involved in ANP secretion, with the former responsible for the initial rapid release and the latter maintaining the secretion.
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: N L
authors.initials: NL
authors.lastname: Wong
authors.forename: E F
authors.initials: EF
authors.lastname: Wong
authors.forename: G H
authors.initials: GH
authors.lastname: Au
authors.forename: D C
authors.initials: DC
authors.lastname: Hu
mesh_terms: D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D004837:Epinephrine / Q000494:pharmacology*; D006321:Heart / Q000502:physiology*; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008729:Methoxamine / Q000494:pharmacology*; D010477:Perfusion; D010646:Phentolamine / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology; D012016:Reference Values
chemical_list: D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D009320:Atrial Natriuretic Factor; D011433:Propranolol; D008729:Methoxamine; D007545:Isoproterenol; D004837:Epinephrine; D010646:Phentolamine