Adenosine attenuation of catecholamine-enhanced contractility of rat heart in vivo.
The antiadrenergic action of adenosine was examined in open- and closed-chest preparations of anesthetized rats. The positive inotropic effects of a jugular vein infusion of either isoproterenol or epinephrine were attenuated by phenylisopropyladenosine, an adenosine A1-receptor agonist. 1,3-Dipropyl,8-cyclopentylxanthine, a specific A1-receptor antagonist, inhibited the action of phenylisopropyladenosine. The results indicate that adenosine receptor-mediated mechanisms are functional in the blood-perfused rodent heart and support the possibility of a physiological role for adenosine in modulating cardiac contractility.
Romano
F D
FD
Department of Physiology, University of Massachusetts Medical School, Worcester 01655.
Naimi
T S
TS
Dobson
J G
JG
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D004837:Epinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000502:physiology; D006352:Heart Ventricles; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014970:Xanthines / Q000494:pharmacology
D014970:Xanthines; D010660:Phenylisopropyladenosine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine; D007545:Isoproterenol; D004837:Epinephrine