The role of magnesium in the endothelial dysfunction caused by global ischemia followed by reperfusion: in vitro study of canine coronary arteries.

Objective: To study the role of magnesium in the endothelial dysfunction of canine coronary arteries caused by cardiopulmonary bypass (CPB) global ischemia followed by reperfusion.

Design: Segments of canine coronary arteries were suspended in organ chambers to measure isometric contraction by prostaglandin F (2alpha), and relaxed by acetylcholine (ACh), sodium fluoride (NaF), calcium ionophore (A23187) and sodium nitroprusside (SNP) in crescent concentrations. The investigation protocol had groups with six dogs: CONTROL group (without CPB), CPB group (105 min of CPB without aortic cross-clamping), ISCH group (45 min of CPB with aortic cross-clamping), ISCH/REP group (45 min of aortic cross-clamping followed by 60 min of reperfusion).