[Interaction between thrombocytes and the coronary system in the presence of SIN 1 and nitroglycerin after...

For further examination of the interaction of platelets with coronary endothelium in more detail, porcine platelets were infused into the coronary system of isolated, Langendorff-perfused rabbit hearts. The hearts were preincubated with very low activity of collagenase inducing functional endothelial lesion characterized by 50% reduction of EDRF-dependent dilation. Platelet infusions into those hearts were accompanied by a sudden myocardial failure and a significant retention of the platelets infused. When in addition to platelets the hearts were perfused with SIN 1 or GTN the global coronary flow did not fall below critical values. Moreover, the platelet recovery was not any longer diminished. After heart passage the platelets aggregation was more inhibited with SIN 1 than with GTN. SIN 1 and GTN in concentrations applicated to the heart could not inhibit porcine platelet aggregation, thus the aggregation behaviour reflects the different availability for platelets of the liberated NO during coronary passage.