These impairments occurred after as early as one week of alcohol administration, when the presence of a fatty liver is first identified. Fatty liver, both non-alcoholic (NAFL) and alcoholic (AFL), affects nearly one-fourth of the U.S. population. Patients with either NAFL (seen in up to 85% of obese individuals) or AFL (seen in the majority
of alcoholics) can progress to hepatitis, fibrosis, and cirrhosis, and fatty liver is no longer considered benign. While we have established that AFL leads to impaired RME, endocytosis in NAFL has Proteasome inhibitor not been studied. Here, we investigated RME and the changes caused in RME in rats exhibiting AFL or NAFL to see if endocytosis defects were a result of alcohol administration, or were seen in all fatty livers.
Methods: Wistar rats were fed liquid control or alcohol diet (Lieber DeCarli, 35% of Dorsomorphin cost calories as ethanol; 35% calories as fat, groups 1 & 2), or lean or high-fat pellets (12% fat or 60% fat, respectively, groups 3 & 4). Carbohydrate (maltose/ dextrin) was similar in all groups. Animals were sacrificed after 8-10 weeks of feeding, and serum, isolated hepatocytes, and intact liver obtained for determination of serum enzymes, histology, fat content, protein content, and measurement of endo-cytosis. Results: Histologically, the AFL and NAFL rats were indistinguishable, showing fatty liver but no signs of steato-hepatitis. Serum ALT and AST were significantly increased in both the AFL
and NAFL rats, as was triglyceride content in hepatocytes and whole liver, compared to many controls. Binding and internalization of 125I- ASOR was determined in isolated hepatocytes, and significant impairments of both processes were found in hepatocytes from alcohol fed animals compared to controls. No difference in binding or internalization, however was found in the hepatocytes isolated from the lean and high fat diets. Western Blot analysis of ASGPR and two Rab proteins known to be important in vesicle trafficking (Rab 3D and Rab 18) showed significant decreases in the AFL, but not the NAFL rats. Conclusions: Our findings suggest that the impairment in endocytosis and vesicle trafficking protein content in the ethanol fed animals is a direct result of the alcohol administration, and not a result of a fatty liver. Future studies examining the activation status of Rabs and content of Rab effector proteins in the AFL model may aid in the development of therapeutic targets. Disclosures: The following people have nothing to disclose: Karuna Rasineni, Daniel Pen-rice, Edward N. Harris, Cliff I. Stains, Jon Beck, Benita L. McVicker, Mark A. McNiven, Carol A. Casey Background: Epidemiologic data link alcoholic liver disease (ALD) to binge drinking and cigarette smoking. Previous studies showed that heavy alcohol or low-level dietary nitrosamine exposures cause steatohepatitis with insulin resistance and oxi-dative stress in experimental animals.