Experimental transplantation of hepatocytes in cases of toxic acute liver failure. An allograft model.

The aim of this experimental study was to modify a rat liver-cell harvesting technique and to evaluate the efficacy of allogeneic liver cell transplantation (Tx) using cyclosporin A immunosuppression in rats with N-dimethylonitrosamine (N-DMNA)-induced acute liver failure (ALF). Twenty male Wistar rats, weighing 190-320 g, were used as donors. Hepatocytes were harvested by the use of a modification of the Seglen portal vein collagenase perfusion technique (type V/1.3 mg/ml), which resulted in the isolation of a mean of 8000 viable clusters of hepatocytes per donor (viability was measured using the trypan blue exclusion test). The male Lewis recipients and controls received 20 mg/kg N-DMNA i.v., and were then divided in three groups. Group 1 (n = 5) received no treatment, group 2 (n = 10) received 5000 clusters of freshly isolated hepatocytes (FIH) in the spleen 24 h after the administration of N-DMNA- and group 3 (n = 10) received 5000 clusters of FIH beneath the renal capsule, 24 h after the administration of N-DMNA. All groups were treated with cyclosporin A 20 mg/kg per day i.p.. SGOT and bilirubin values were measured and all surviving rats were sacrificed on day 14. All rats in group 1 died of histologically confirmed liver necrosis within 72 h. The 14-day survival was 60% in group 2 and 50% in group 3. The post-Tx SGOT values reached their maximum on days 3-4 (group 2, mean 754; group 3, mean 529) and were only slightly elevated on day 14 (group 2 = 75, group 3 = 48). The post-Tx bilirubin values reached their maximum on days 3-5 (group 2 = 1.1, group 3 = 1) but failed to return to normal until day 14. Autopsy and histological examination of the surviving animals showed well-preserved hepatocellular spherical aggregates in the spleen and hepatocellular "cords" in the kidney accompanied by signs of regeneration of the native liver. We concluded that the hepatocyte Tx in a rat experimental allo-Tx model improved the survival rate and the SGOT values in cases of toxic ALF. Survival rates between the two different sites of Tx were similar.