[Lysosomal lesions during a course of acute experimental muscular ischemia. Protective effect of a polypetitide proteinase inhibitor]

Three groups of rabbits were used: a) with acute ischaemia in a rear limb; b) with acute ischaemia in a rear limb and treated with i.v. 100,000 KIU of a proteinase-inhibitor polypeptide extracted from ox lung; c) normal controls. Acute ischaemia was obtained by ligature of the ipsilateral common iliac, external iliac, inferior epigastric and femoral arteries. Soluble and total activity of 3 lysosomal enzymes (cathepsin, acid phosphatase and N-acetyl-glucosaminidase) were determined in gastrocnemius muscle from all 3 groups. The mean ratio between bound and soluble activity for all 3 enzymes in normal gastrocnemius muscle was higher than in ischaemic muscle, but not significantly different from that in ischemic muscle of animals treated with the polypeptide. Furthermore, this ratio in ischemic muscle was significantly lower than that of ischemic muscle of the rabbits treated with the polypeptide. These data suggest that the polypeptide offers protection against lysosomal lesion in the course of experimental ischaemia of the skeletal muscle.