Acute arterial occlusion of the extremities may result in severe and complex metabolic derangements. In order to investigate therapeutic means of controlling such metabolic derangements, 19 adult mongrel dogs weighing between 7 and 15 kg underwent acute arterial occlusion by cross-clamping the infrarenal aorta. Clamping was released after 48 hours. The experimental animals were divided into three groups: an untreated group, a THAM group, and a perfusion group. Biochemical and electrolyte analyses were measured before and 1 hour after occlusion, and 1, 3, 12, 24, and 48 hours after the release of occlusion. The SGOT, creatinine, CPK, and aldolase levels rose after release of the occlusion and were significantly higher in the untreated group than in the THAM and perfusion groups. Among these enzymatic changes, the CPK level showed the largest increase. The serum potassium levels remained almost at preocclusion levels after release of the occlusion. It was concluded that the intravenous administration of THAM and peripheral washing were effective against untoward metabolic changes occurring in the ischemic extremities.