ABSTRACT
Objective To investigate the effects of perfusion pressure with a cardioplegic solution on endothelium-dependent relaxation and smooth muscle function of porcine coronary artery. Methods The hearts were infused with a modified St.Thomas’ hospital solution at the pressures of 40, 60 and 80 mmHg. The distal part of porcine left anterior descending coronary artery (LAD) having a diameter of 1.0-1.5 mm, was dissected free from the surrounding tissue, cut into 1 mm long segments, immediately transferred to organ baths for the evaluation of endothelial and smooth muscle function. Results Smooth muscle function was not affected after cardioplegic flushing at the pressures used in this study. The maximal endothelium-dependent relaxations of the vessels in 40 and 60 mmHg groups were not reduced compared to fresh segments . The maximal EDR was significantly reduced to (90.8?2.2)% (P