ULTRASTRUCTURE OF REPERFUSED SKELETAL-MUSCLE - THE EFFECT OF OXYGEN RADICAL SCAVENGER ENZYMES

The aim of the present study was (1) to examine changes in ultrastruct ure and subcellular volume fractions in reperfused skeletal muscle and (2) to examine the effect of pre-plus postischaemic treatment with ox ygen radical scavenger enzymes. Experiments were performed in 8 pentob arbital anesthetized dogs. The gracilis muscle was denervated and vasc ularly isolated on both lower limbs, except for the main artery and ve in. A catheter was advanced through the distal end of the femoral arte ry for supply of superoxide dismutase (SOD) and catalase (each enzyme 12,000 U/10 min prior to ischaemia and 36,000 U/30 min at reperfusion) through the muscle artery to the muscle on one side. A catheter in th e muscle vein secured the collection of venous blood to avoid a supply of SOD and catalase to the other muscle. Ischaemia was induced on bot h sides by clamping the branch of the femoral artery supplying the mus cle for 4 h, and the muscle was thereafter reperfused for 1 h. Ultrast ructural examination (morphometric by point counting and semiquantific ation) of the reperfused tissue revealed mitochondrial damage, margina tion of nuclear chromatin, lipid droplets, filamental disruption, as w ell as oedema in both endothelial and myofibrillar cells. In addition some influence of treatment with SOD and catalase could be seen, mainl y in reduction of the number of micrographs with cellular oedema and e specially oedema in endothelial cells.