Cyclosporine and partial liver allotransplants in a simplified rat model.

We designed a simplified rat model to assess the effects of cyclosporine (CsA) on liver transplants. Auxiliary liver grafts consisting of 20 per cent of the whole liver were supplied with portal inflow and the bile was drained into the stomach. The cuff technique was used routinely for both end-to-end and end-to-side venous anastomoses. The host liver was totally deprived of portal inflow. Two inbred strains of rats, LEW and F344, were used for isograft (LEW----LEW) and allograft (F344----LEW). All survivors were killed at the end of the fourth week after transplantation. During four weeks, the isografts increased by 108 per cent in wet liver weight. Animals with allograft were treated with CsA given i.m., in a daily dose of 20 and 40 mg/kg for the first ten days post transplantation. The CsA-treated rats were free from parenchymal destruction of the allograft, as was characteristic of the allograft controls. The rats given CsA in the dose of 40 mg/kg showed a 173 per cent increase in the wet liver weight of the transplant, such being greater than allografts in rats on 20 mg/kg of CsA (100 per cent) and even than isografts. These results indicate that auxiliary partial liver grafts benefit from the use of CsA not only through suppression of allorejection but through a potential "hepatotrophic effect" of the agent.