Successful orthotopic liver transplantation (OLT) can be achieved in the rat. We used bromo-2-deoxyuridine (BrdU) as a proliferation marker to document morphological differences between OLT with and without rearterialization. Animals with portal anastomosis alone had a significantly increased proliferation rate of hepatocytes, Kupffer cells, and bile duct epithelial cells, as indicated by strong staining with BrdU, 8 days post-transplant compared to animals with rearterialization. Regeneration of ischemically damaged liver parenchymal cells may account for this observation. Thus, OLT with rearterialization appears to be the more physiological transplant model.