Oxidative stress and cardiac microvascular structure in XXXX and reperfusion: the protective effect of antioxidant vitamins.

@entity9492 @entity63 @entity620 @entity2041 @entity22143 @entity1881 @entity35 @entity1865 @entity130
Reperfusion of the @entity63 myocardium results in structural changes in the capillary bed, which may contribute to decreased microcirculatory flow ("no reflow"). This study was designed to correlate the endothelial cell shape changes with both oxidative stress and lipid peroxidation and to evaluate the beneficial potential of @entity22143 (a hydrophilic analogue of @entity1881 ) and @entity620 . Isolated buffer-perfused @entity35 hearts were made @entity63 for 45 min and then reperfused with 100 microM @entity22143 and/or 100 microM @entity620 . Morphological changes were quantified by measuring capillary cross-sectional areas. Increased myocardial content of @entity9492 and its release into the coronary effluent were used as indices of oxidative stress. Myocardial @entity1865 , an end product of lipid peroxidation, was also measured. Luminal membrane blebs and capillary "constriction" in the @entity63 groups occurred when there was no change in either @entity2041 status or @entity1865 concentrations. Reperfusion altered the redox state of the heart sufficiently to induce lipid peroxidation. It also induced endothelial cell swelling and a reduction in luminal area. @entity620 was a more effective antioxidant than @entity22143 as it significantly reduced both oxidative stress and @entity130 . The combined antioxidant treatment returned both the stress ratio and the capillary measurements to control values. We conclude that endothelial cell swelling correlates with the degree of oxidative stress and that antioxidant vitamins reduce membrane damage by preventing lipid peroxidation.
