Objective    To investigate the expression of endoplasmic reticulum molecular chaperone

glucose regulated protein 78 (GRP78)

in the liver tissues during fatty diet-induced nonalcoholic steatohepatitis (NASH) in rats and explore the role of endoplasmic reticulum stress in pathogenesis of nonalcoholic steatohepatitis.     Methods    Rat model of nonalcoholic steatohepatitis were established with fatty dieting. Blood samples were collected to detect serum aspartate transaminase (AST)

alanine aminotransferase (ALT)

free fatty acid (FFA) and triglyceride (TG). Liver tissues were obtained to measure malondialdehyde (MDA) content. The expression of GRP78 in the liver was detected with RT-PCR and Western blot analysis.     Results    Compared with the control group

the serum contents of ALT

AST

FFA and TG and liver content of MDA in NASH were increased. The expression of GRP78 at protein and gene levels were increased in NASH in a time-dependent manner

and reached peak in 16 weeks (P0.01).     Conclusion    Enhanced expression of GRP78 could be induced by fatty diet. The excessive expression of GRP78 could result in the endoplasmic reticulum stress

and thus lead to fatty acid abnormal deposition

which might be closely involved in NASH.