Ischemia-reperfusion syndrome: an alternative experimental model.

OBJECTIVE: To design an alternative experimental model of ischemia-reperfusion syndrome. Our model mimics the clinical pattern of the syndrome and also assesses the efficacy of therapeutical protocols. EXPERIMENTAL DESIGN: Ischemia was induced under general anaesthesia in the posterior limbs of 10 sheep by occluding the aorta and vena cava by means of two-way balloon catheters. Ischemia was stopped after 4 hours and blood and histologic parameters determined in the first three hours of revascularization. The animals were divided into three groups: a group of 3 sheep in which a sham operation was performed; a control group (5) to assess the efficacy of induced ischemia; the third group (5) to determine the effect of antioxidant and membrane protective drugs to assess the reliability of the model to study the ischemia-reperfusion syndrome. RESULTS: At the end of ischemia, skin temperature was decreased (p < 0.04) both in control and treated groups, pH decreased significantly soon after reperfusion in the control group (p < 0.04). Reperfusion in control sheep, compared with treated animals, was followed by a significant increase in CPK blood levels (p < 0.009), related to marked muscle damage, in particular after reperfusion. Tissue damage detected at TEM was less severe in treated animals. CONCLUSIONS: This model is an effective experimental strategy and a means of assessing preventive treatment.