title: Function of the coronary arterial collateral network in healthy myocardium: studies of peripheral coronary pressure in the dog.
abstract: Coronary collateral arterial network function was studied in normal dog myocardium using measurements of peripheral coronary pressure (pressure measured distal to a ligature in a branch of the anterior descending coronary artery). Free communication between all parts of the anastomotic network was demonstrated. Adrenaline infusion raised systolic and diastolic levels of peripheral coronary pressure both when the systemic blood pressure was allowed to rise and in experiments where rise in systemic arterial pressure was prevented by haemorrhage. It is suggested that myocardial contraction pressurizes the subendocardial network thus facilitating perfusion of postnetwork vessels. This effect prolongs the time during which coronary vessels affected by rising intramyocardial pressure in systole can be perfused during the cardiac cycle. Additional evidence is presented to indicate the existence of a critical closing pressure in the coronary circulation at about 1.7 kPa (12.8 mmHg).
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000502:physiology*; D004285:Dogs / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006321:Heart / Q000502:physiology*; D006470:Hemorrhage / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D010477:Perfusion
chemical_list: D004837:Epinephrine