title: Adenosine receptors mediating cardiac depression.
abstract: Several adenosine analogs were evaluated for their effects on rate and contractility in guinea pig isolated atria. Among adenosine agonists, (-)-N-(1-methyl-2-phenylethyl) adenosine (l-phenylisopropyladenosine; l-PIA) and N-cyclohexyladenosine (CHA), decreased rate and force at nanomolar concentrations, whereas 2-chloroadenosine, N,N-dimethyladenosine (N6-dimethyladenosine) and (+)-N-(1-methyl-2-phenylethyl)adenosine (d-phenylisopropyladenosine; d-PIA) were less potent cardiac depressants. The degree and order of potency of these agonists suggest that the cardiac depressant effects of adenosine are mediated via A1-receptors. The cardiac depressant effects of CHA and l-PIA were antagonized by theophylline and 1,3-diethyl-8-phenylxanthine (DPX).
mesh_terms: D015762:2-Chloroadenosine; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003864:Depression, Chemical; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
chemical_list: D014970:Xanthines; D015762:2-Chloroadenosine; D010660:Phenylisopropyladenosine; C027512:1,3-diethyl-8-phenylxanthine; C027513:N(6)-cyclohexyladenosine; D013806:Theophylline; D000241:Adenosine