The effect of long-term arterial occlusion on energy metabolism of the human quadriceps muscle

Abstract

The effect of 1.5-2.5 h tourniquet ischemia on energy metabolism of the quadriceps muscle was studied using percutaneous needle biopsy technique in 16 patients operated on for an inveterated knee injury. During occlusion there was a moderate decrease in ATP with an increase in ADP and AMP. This change resulted in a decreased energy charge potential. At the same time phosphorylcreatine (PC) decreased markedly while creatine (Cr) increased, giving a constant total creatine (TCr). An accumulation of lactate during occlusion with values up to 80 mmol/kg d.m. (dry muscle) was observed. A 15% reduction in glycogen was calculated. After release of the tourniquet, the active phosphate concentration and the energy charge potential returned to basal levels within 5 min and most of the metabolites in the glycolytic sequence were normalized. Muscle lactate content was normal after 30 min of intact circulation. Long term tourniquet ischemia apparently induces marked changes in energy metabolism in skeletal muscle, but the changes are rapidly and completely reversible with restoration of blood flow.