The effects of beta-adrenergic agents on the contractility of transplanted canine heart.
The effects of isoprenaline and adrenalin on the myocardial contractility of transplanted heart were studied in 6 mongrel dogs which had undergone orthotopic cardiac transplantation. Isoprenaline and adrenaline produced a fall in end-diastolic and end-systolic volumes, and an increase in stroke volume, cardiac output and velocity of contraction when the heart rate was increased. Similar changes were observed in 4 mongrel dogs tested as controls, with the exception of a less pronounced increase of cardiac output after administration of isoprenaline and adrenalin and a fall in stroke volume associated with a higher acceleration of heart rate after administration of isoprenaline. These minor differences between the transplanted and intact heart were thought to be a reflexion of the increased blood volume following heart transplantation.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D004837:Epinephrine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D016027:Heart Transplantation; D007545:Isoproterenol / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects*; D014184:Transplantation, Homologous
D007545:Isoproterenol; D004837:Epinephrine