RÉSUMÉ
<p><b>OBJECTIVE</b>To evaluate the effects of human mesenchymal stem cells (hMSCs) transplantation via portal vein to treat acute liver injury in mice induced with acetaminophen.</p><p><b>METHODS</b>A model of acute liver injury was established by acetaminophen gavage with a dose of 500 mg/kg. Twenty severe combined immune deficient mice (SCID mice) were randomly divided into 2 groups; one with hMSCs transplantation via their portal veins, the other group served as controls and only saline was infused into their veins. Liver function tests, fluorescein staining and reticular fiber staining of liver histological preparations and fluorescence- and light-microscopy were applied to observe the biochemical and pathological changes in the mice before and after the transplantation of hMSCs.</p><p><b>RESULTS</b>Liver function of the hMSCs group was significantly better than that of the controls (P less than 0.05). Fluorescence microscopy revealed that the hMSCs appeared in the areas of the periportal veins at first and then extended to the central vein areas; the reticular fiber staining indicated that hMSCs could repair the architecture of the hepatic acini. No prominent fibrosis and pseudolobules were found.</p><p><b>CONCLUSIONS</b>hMSCs transplantation via portal vein to SCID mice with acute liver injury induced by acetaminophen can improve their liver function effectively; hMSCs growth in their livers and acinus reconstruction can be affected. We think it is a good method to treat acute liver injury.</p>