Coronary Circulation and Kinin Release after Experimental Obstruction of the Left Anterior Descending (LAD) Coronary Artery in the Pig

Abstract

A 30-minute occlusion of the Left Anterior Descending (LAD) coronary artery in the pig had no significant effect on the heart rate, left ventricular and aortic pressures or resting coronary flow. However there was a significant increase in kinin levels in the blood sample drawn from the coronary sinus, but not the one drawn from the aorta. The levels in the sinus were significantly (p<0.05) different from the one in the aorta. The concentrations of blood gases also showed differences in the sinus and the aorta: Oxygen (02) was gradually decreasing in the sinus with a corresponding rise in Carbon dioxide CO2 tension from zero to 30 minutes of the occlusion. There were however no differences in the values of Haematocrit, Hemoglobin and pH in both the sinus and aorta samples after the occlusion.
These results tend to indicate that the magnitude of flow reduction is related to the size of ischaemia. It also indicates that kinin measurement in the sinus may be used as a marker to demonstrate flow characteristics.