ISCHEMIA-REPERFUSION OF HUMAN SKELETAL-MUSCLE DURING AORTOILIAC SURGERY - EFFECTS OF ACETYLCARNITINE

Our previous study on human skeletal muscle undergoing ischemia and re perfusion has revealed that granulocytes, which infiltrate the muscle tissue in large numbers, play an important role in mediating fibre inj uries by producing superoxide anion (O-2(-)) which is responsible for membrane lipid peroxidation. In the current study, five patients under going aortic reconstructive surgery were given acetyl-carnitine (2 mg/ kg i.v. plus 1 mg/kg/min for 30 min) prior to the induction of ischemi a. Muscle biopsies and blood samples were examined: a) after anaesthes ia; b) at the end of ischemia; and c) 30 min after reperfusion, with t he aim of elucidating whether acetylcarnitine could prevent the infilt ration and/or the activation of granulocytes and eventually skeletal m uscle injuries. During ischemia and reperfusion complement activation recruited numerous granulocytes into the muscle tissue, but, contrary to the untreated samples, the ability for O-2(-)-generation of these c ells remained at low levels and was comparable to that of ischemia eve n when molecular O-2 was reintroduced to the tissue. Accordingly, the morphological changes of the postischemic muscle fibers were substanti ally reduced when compared to the untreated samples; in fact, the mito chondrial swelling was only moderate and the intramitochondrial dense bodies were small and scarce. The current findings support a positive role of acetyl-carnitine in ameliorating the ischemia-reperfusion (I-R )-induced damage of human skeletal muscle.