Peripheral nerve ischemia: Part 2. Accumulation of organelles.

Following simultaneous ligation of the aorta and femoral artery in the cat, organelles accumulated in distal portions of the sciatic nerve and in lower portions of the tibial and peroneal nerves. The accumulations were located in the proximal and distal ends of the nerve infarction and delineated the borders of the necrotic area. Topographical analysis of the necrosis and organelle accumulations following ligation of these main arteries showed the larger nerve fascicles to be more sensitive to ischemia than the smaller ones. The center of a nerve fascicle was more sensitive than the periphery. The organelles accumulated in ischemic nerves during the first hours after arterial ligation, presumably as a result of lack of energy for fast axoplasmic transport. Later accumulations reflected mechanical block of axoplasmic transport due to focal necrosis of the nerve. The content of organelle accumulations was similar to that found in lesions resulting from transection except for the presence of 60 to 70 A filaments at the distal end of the infarction.