Alcohol dehydrogenase and aldehyde dehydrogenase (ADH and ALDH) have been coencapsulated into mouse erythrocytes by an electroporation technique. The optimal conditions were achieved as follows: 420 V, four pulses of 1 ms every 15 min. at 37 degrees C, completed by resealing: 1 h at 37 degrees C. An encapsulation yield ranging from 11-12% was obtained for ADH+ALDH-loaded erythrocytes. Carrier cell recovery was 52%. Electroporated-RBCs observed under Scanning electron microscopy exhibited a tendency toward invaginated sphero-stomatocytes. These invaginations were not found in electroporated/resealed RBCs. The intravenous administration of 51Cr-RBCs manifested a bimodal pharmacokinetic profile: an initial phase (t1/2alpha) with a rapid decrease of plasma 51Cr-RBCs followed by a slow and prolonged elimination phase (t1/2beta). The values corresponding to in vivo survival rate during the elimination phase indicated that the survival rate of 51Cr-electroporated loaded-RBCs was slightly lower (t1/2beta, 4.5 days) than 51Cr-native RBCs (t1/2beta, 5.3 days). The mean clearance values from blood of electroporated 51Cr-RBCs (unloaded and loaded) were higher (0.51 %51Cr/day and 0.54 %51Cr/day, respectively) than the obtained for native 51Cr-RBCs (0.18 %51Cr/day). The target organs for electroporated RBCs proved to be the same as for native RBCs. However, electroporated RBCs showed highest accumulation in liver, spleen and lung, since they were promptly recognized by the reticuloendothelium system. Mice induced to the state of acute ethanol intoxication and treated with ADH+ALDH-RBCs clearly showed a lower level of ethanol concentration in plasma (less than 43% ethanol) than the intoxicated mice treated with native RBCs. En consequence the clearance values of ethanol from blood in intoxicated mice treated with ADH+ALDH-RBCs (0.39 ml/min) were higher than the treated with native RBCs (0.20 ml/min). The results obtained suggest that ADH+ALDH-loaded erythrocytes could be used as a potential carrier system for in vivo removal of high levels of ethanol from blood caused by excessive alcohol consumption.