Relative effect of CO2 on canine coronary vascular resistance.

Relative effect of CO2 on canine coronary vascular resistance.

We determined the effect of alterations in coronary arterial PCO2 on coronary vascular resistance (CVR) at a constant coronary sinus (CS) PO2 and the effect of coronary arterial PO2 variation on CVR at a constant CS PCO2. A linear but opposing effect on CVR was found for both gases. The sensitivity of CVR to O2 change, represented as CVR/CS PO2, was approximately twice that of the ratio CVR/CS ...

The response of canine coronary vascular resistance to local alterations in coronary arterial P CO2.

The effect of hypercapnia on coronary vascular resistance (CVR) was studied in seven open-chest dogs. Coronary blood flow was supplied to the cannulated left main coronary artery from the femoral artery by a precision pump. Coronary arterial PCO2 was locally controlled with a small membrane oxygenator in the coronary perfusion circuit. Each PCO2 change was made at a constant coronary flow, and ...

The neurogenic vasoconstrictor effect of digitalis on coronary vascular resistance.

The coronary vasoconstrictor properties of digitals were evaluated in 61 anesthetized, openchest dogs after coronary sinus cannulation and under conditions of a constant heart rate (atrioventricular pacing) and near-constant blood pressure. The contribution of alpha adrenergic receptor stimulation to the digitalis-induced increase in coronary vascular resistance (CVR) was examined. With Na pent...

Propranolol on Coronary Vascular Resistance

Propranolol on Coronary Vascular Resistance