Receptor-specific effects of acute rejection after heart transplantation on endothelium-dependent coronary relaxation in dogs.
To establish the effects of acute rejection on coronary artery endothelial reactivity in a canine model of heart transplantation, we submitted seven mongrel dogs to heterotopic heart transplantation without immunosuppression for a period of 7 days. At harvesting, all transplanted hearts displayed a grade IV histologic rejection. Compared with native heart, the endothelium-dependent relaxation of the coronary arteries from the graft displayed an increased sensitivity to serotonin, a decreased sensitivity to thrombin, and no change in the response to acetylcholine and adenosine diphosphate; endothelium-independent relaxation to sodium nitroprusside was not affected. Therefore, in the canine heterotopic heart transplant model, acute rejection has no effect on endothelium-independent relaxation of coronary arteries but affects endothelium-dependent relaxation in a receptor-specific manner.
Bouchard
D
D
Department of Cardiovascular Surgery, Montreal Heart Institute, Quebec, Canada.
Cartier
R
R
Despatis
M A
MA
Carrier
M
M
Leung
T K
TK
D000109:Acetylcholine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D006084:Graft Rejection / Q000276:immunology / Q000503:physiopathology*; D016027:Heart Transplantation / Q000276:immunology / Q000502:physiology*; D009599:Nitroprusside / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D016042:Transplantation, Heterotopic
D009599:Nitroprusside; D012701:Serotonin; D000244:Adenosine Diphosphate; D013917:Thrombin; D000109:Acetylcholine