Structural Alterations of Skeletal Muscle Induced by Ischemia and Reperfusion

Hans Appell, Sabine Glöser, José Soares, José Duarte
1999 Basic Appl. Myol   unpublished
The purpose of the study was to undertake a series of experiments with varying time periods of ischemia followed by reperfusion to investigate the effects on muscle morphology. Charles River mice received a tourniquet at their right limb for 60, 90, and 120 minutes, respectively , under general anesthesia which was followed by a reperfusion period of 60 minutes (n = 5 in each group). Their soleus muscles were removed, the left one serving as contralateral control, and processed for light and
more » ... ed for light and electron microscopic examination. Muscle fiber cross sectional areas and the thickness of the capillaries basement membranes were evaluated morphometrically. Capillary endothelial ultrastructure showed considerable pathological alterations extending to intracellular edema, and the basement membrane was thickened by about 50%. The muscle fibers were reduced in size, which depended on the period of ischemia (15-23%). Skeletal muscle morphology showed mitochondrial disturbances , condensation of contractile material, presence of lysosomes, and focal fiber necro-sis, which also seemed to be aggravated the longer the ischemic period had lasted. The in-terstitial space was widened speaking in favor of an intramuscular edema. It is concluded that skeletal muscle morphology is severely affected under conditions of ische-mia/reperfusion and that the capillary endothelium is mainly involved in the pathophysio-logical mechanisms.