DIETARY MAGNESIUM IMPROVES ENDOTHELIAL-DEPENDENT RELAXATION OF BALLOON INJURED ARTERIES IN RATS

The purpose of the present study was to examine the importance of magn esium in endothelial function after arterial balloon injury. Male Wist ar rats were fed normal, high or low concentrations of magnesium. Thre e weeks later the animals underwent endothelial injury of the thoracic aorta by a balloon catheter or a sham operation. Biochemical, histolo gical and endothelial function analysis were performed 15 days after t he surgical treatment. The animals fed a low magnesium diet presented the lowest level of serum magnesium and the highest ionized blood calc ium levels. Histomorphometric analysis revealed no differences among g roups neither regarding the magnitude of intimal thickening nor the re covery of endothelial coverage. However, when vasoreactivity responses were compared in the balloon-injured group, those animals fed a high magnesium diet had the better endothelium-dependent vascular relaxatio n. In conclusion, a higher magnesium level in the diet was beneficial to vessels that underwent endothelial injury by balloon catheter. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.