Detection of Endoplasmic Reticulum Stress and Progression of Steatohepatitis in Mink (Neovison vison) with Fatty Liver

Abstract

This study used the non-alcoholic steatohepatitis activity index (NAI), presence of fibrosis and Mallory-Denk bodies (MDBs), and quantification of glucose regulated protein 78 (GRP78) messenger ribonucleic acid (mRNA) as indicators of steatohepatitis development and recovery in the American mink (Neovison vison). Mink were fasted for 0, 1, 3, 5, or 7 days, and one group re-fed 28 days post 7-day fast. Liver NAI indicated that moderate fatty liver developed after 5 days of fasting. Liver recovery was achieved after the re-feeding period. There was no evidence of fibrosis or MDB formation. Upregulation of GRP78 was observed by day 7 of fasting indicating endoplasmic reticulum stress. This effect was greater in females. Results suggest that liver steatosis did not advance to steatohepatitis within a 7-day fast. However, should the length of fast be increased the mink may be at risk. Results also show that liver recovery from simple fatty liver is possible.