Pentoxifylline Improves Skeletal Muscle Recovery After Acute Ischemic and Reperfusion Injury

Abstract

Purpose: Skeletal muscle ischemia is associated with complex interactions involving neutrophils, erythrocytes, oxygen free radicals, and complement factors that lead to development of reperfusion injury on restoration of blood flow. Pentoxifylline is known to decrease neutrophil margination, improve erythrocyte passage through the capillary system, and possibly serve as an oxygen radical scavenger. The authors hypothesized that the addition of pentoxifylline to the reperfusate might improve muscle recovery after acute ischemic injury. Methods: Twenty-four New Zealand White rabbits underwent vascular isolation of both hind limbs, leaving the external iliac and femoral arteries as sole inflow arteries for each respective limb. The animal was secured to an operating board such that each tibialis anterior muscle was attached to a force transducer, and muscle contractions after maximal tetanic stimulation were recorded on an oscilloscope at timed intervals. Acute occlusion was induced in the right hind limb by use of removable vascular clips and continued until < 15% of contralateral limb function was achieved. The animal was then (continued on next page) (Abstract continued) reperfused with saline "control " or pentoxifylline (50 mg/kg) "treated." Muscle function was recorded in each limb at 5, 30, 60, 90, and 120 minutes after reperfusion. Results: A continual trend of muscle function improvement was noted in the pentoxi fylline-treated group, reaching statistical significance compared with controls after 30 minutes (16.8% of contralateral limb; P<0.04) and 120 minutes (36.7% of contralat eral limb ; P<0.04) of reperfusion. Control animals failed to demonstrate significant improvement in muscle function over the 2-hour reperfusion period. Conclusion: Pentoxifylline improved muscle function recovery after acute ischemic injury in the rabbit hind limb model.