Administration of tourniquet. I. Are edema and oxidative stress related to each other and to the duration of ischemia in reperfused skeletal muscle ?

One hindlimb of mice was subjected to 60, 90 and 120 min ischemia by application of a tourniquet followed by a 60-min reperfusion period. An additional experimental group received a tourniquet for 90 min without subsequent reperfusion. The soleus muscle (from the contralateral side also as control) was removed and evaluated for muscle weight, protein weight, protein content, and glutathione concentrations. Ischemia alone without subsequent reperfusion did not produce significant changes. With postischemic reperfusion, the protein content and muscle weight increased, probably because of an increased capillary permeability, leading to muscle edema. Oxidative stress was also present during reperfusion, correlating well with the changes in protein content. The intensity of these alterations appeared to depend on the period of ischemia.