Apoptosis and Bcl‐2 Protein Expression in Experimental Alcoholic Liver Disease in the Rat

We used the intragastric feeding rat model to investigate the relationship between severity of alcoholic liver injury, apoptosis, bcl‐2 protein expression, and lipid peroxidation. Rats were fed ethanol with different dietary fats (saturated fat, corn oil, and fish oil) for a 1‐month period. Apoptosis was evaluated using an immunohistochemical method, and flow cytometry. Bcl‐2 protein concentrations in liver were evaluated by Western blot analysis and lipid peroxidation by measurement of conjugated diems. Pathological changes (fatty liver, necrosis, and inflammation) were present in com oil‐ethanol and fish oil‐ethanol groups only. The highest number of apoptotic cells were seen in the group of rats exhibiting her Injury. The fish oil‐ethanol‐fed group had the highest concentrations of bcl‐2 protein; this protein was localized in the bile duct epithelial and inflammatory cells. A significant correlation was seem between bcl‐2 protein assessed densitometrically and the number of inflammatory cells/mm² (r= 0.78, p < 0.02) and conjugated diene levels (r= 0.82, p < 0.01). Increased numbers of apoptotic cells were seen in rats developing ethanol‐induced pathological liver injury. Increased bcl‐2 protein concentrations are associated with the presence of inflammatory cells and lipid peroxidation.