Adenosine is not the sole vasodilator released on exposure of isolated guinea-pig hearts to histamine and isoprenaline.
1. The role of adenosine in the control of coronary vessel tone was studied using two guinea-pig hearts in series. Vasodilatory mediator(s) released by the donor heart were assayed by the recipient heart. 2. Adenosine deaminase reduced the activity of vasodilatory mediator(s) released by histamine and isoprenaline by 58.0 +/- 14.4% and 80.5 +/- 5.9% respectively; responses to exogenous adenosine were abolished. 3. Adenosine deaminase added to the donor perfusate supplying the recipient heart caused a significant increase in basal perfusion pressure. 4. Our results suggest adenosine is not the sole mediator of vasodilation in stressed hearts and additionally unstressed hearts appear to release a basal vasodilatory level of adenosine.
School of Biological Sciences/Frances Harrison College of Healthcare, University of Surrey, Guildford, England.
A N
AN
Wilson
K J
KJ
Broadley
D000109:Acetylcholine / Q000494:pharmacology; D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D006632:Histamine; D000243:Adenosine Deaminase; D000241:Adenosine; D007545:Isoproterenol; D000109:Acetylcholine