gms | German Medical Science

Introduction: Non-alcoholic fatty liver disease (NAFLD) has become an increasing common disorder in recent years. However, selection of the optimal model to study the response of a fatty liver to surgical stress such surgical manipulation is difficult as limited data are available characterizing the different animal models. This study was designed to investigate 3 different nutritional models of NAFLD in respect to the time course and intensity of fatty changes and their impact on liver regeneration after 70% partial hepatectomy in Lew rats.

Materials and methods: Male LEW rats were fed with either low methionine-low choline diet (FLD), modified methionine-choline deficient plus high fat diet (MCD+HF) or methionine-choline deficient diet (MCD) for 1, 2, 4, 6 weeks and 3 months. All rats were subjected to 70%PH at the end of feeding time and harvested 24H later. Microcirculation was assessed at both time points by OPS, and the extent of fatty changes by histology. Stress response was evaluated based on body and liver weight recovery as well as clinical chemistry and BrdU proliferation index.

Results: Rats subjected to the pure MCD diet lost about 25% of body weight within the first 6 weeks of feeding whereas rats receiving other food were gaining weight. Fatty changes were visible after one week of feeding when using MCD+HF and MCD, but not when using “fatty liver diet”. These results were confirmed by histology showing almost no changes in the “fatty liver”-group, but abundant small and few large vacuoles in 50-100% of the hepatocytes in the two other groups. In the MCD-group we also observed single necrotic hepatocytes. Liver regeneration was most pronounced in MCD group

Conclusion: MCD+HF did induce substantial fatty changes within a short period of time and was well tolerated, even when rats were subjected to surgical stress.