title: Adenosine-stimulated atrial natriuretic peptide release through A1 receptor subtype.
abstract: Adenosine acts as an important protector of ischemic myocardium through coronary vasodilation and the depression of cardiac contractility. The protective effect of adenosine may partly relate to the cardiac hormone atrial natriuretic peptide (ANP). The aim of the present study was to investigate the effects of adenosine and the adenosine receptor subtype on atrial hemodynamics and ANP release using isolated perfused beating rat atria. Adenosine, a nonselective adenosine receptor agonist, increased the ANP release with negative inotropism in a dose-dependent manner. Adenosine-stimulated ANP release was attenuated by a selective A1 antagonist but not A(2A) antagonist or A3 antagonist. The order of potency of the various agonists for the ANP release was A1 agonists>>A3 agonist=adenosine>A(2A) agonist. The order of potency for the negative inotropy was A1 agonists>adenosine=A(2A) agonist>A3 agonist. The negative inotropism and ANP release by a specific A1 agonist (N6-cyclopentyl-adenosine) were also attenuated by A1 antagonist but not A(2A) antagonist or A3 antagonist. Treatment with A1 agonist resulted in a decrease of cAMP contents in atria and perfusates. The agonist-stimulated ANP release was significantly attenuated in the presence of forskolin, isoproterenol 8-Br-cAMP, or an adenylyl cyclase inhibitor. These results suggest that the A1 receptor subtype is responsible for the adenosine-induced ANP release and negative inotropism through adenylyl cyclase-cAMP pathway.
authors.affiliation: Department of Physiology, Medical School, Center for Healthcare Technology Development, Chonbuk National University, Jeonju, Korea.
authors.forename: Kuichang
authors.initials: K
authors.lastname: Yuan
authors.forename: Chunhua
authors.initials: C
authors.lastname: Cao
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Sung Zoo
authors.initials: SZ
authors.lastname: Kim
authors.forename: Suhn Hee
authors.initials: SH
authors.lastname: Kim
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology*; D058907:Adenosine A1 Receptor Agonists; D058916:Adenosine A1 Receptor Antagonists; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D016275:Atrial Function / Q000187:drug effects; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043682:Receptor, Adenosine A1 / Q000502:physiology*; D014970:Xanthines / Q000494:pharmacology
chemical_list: D058907:Adenosine A1 Receptor Agonists; D058916:Adenosine A1 Receptor Antagonists; D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D043682:Receptor, Adenosine A1; D014970:Xanthines; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; C048599:N(6)-cyclopentyladenosine; D009320:Atrial Natriuretic Factor; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000241:Adenosine; D007545:Isoproterenol