Coronary myogenic responses to abrupt changes in aortic blood pressure in anaesthetized dogs.
A transient increase in coronary transmural pressure was produced in anaesthetized dogs by occlusion of the descending thoracic aorta. Aortic blood pressure (ABP), left ventricular pressure and coronary flow were measured; coronary vascular resistance (CVR) was calculated. Results were similar in innervated and denervated hearts. Occlusion for 10 and 20 s resulted in no change in CVR for 15 s, followed by a metabolic dilatation attributable to enhanced oxygen demand; after release the fall in ABP resulted in an immediate increase in CVR, caused by vascular elastic recoil, followed by hyperaemia.
Dambrosio
M
M
Istituto di Anestesiologia e Rianimazione, Università di Bari, Italy.
Gattullo
D
D
Linden
R J
RJ
Losano
G
G
Pagliaro
P
P
Vono
P
P
D000758:Anesthesia; D000818:Animals; D001011:Aorta / Q000502:physiology*; D001794:Blood Pressure; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000502:physiology*; D004285:Dogs; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D014655:Vascular Resistance