Immunohistochemical characterization of hepatic malondialdehyde and 4-hydroxynonenal modified proteins during early stages of ethanol-induced liver injury

Alcohol Clin Exp Res. 2003 Jun;27(6):1015-22. doi: 10.1097/01.ALC.0000071928.16732.26.


Background: Chronic ethanol consumption is associated with hepatic lipid peroxidation and the deposition or retention of aldehyde-adducted proteins postulated to be involved in alcohol-induced liver injury. The purpose of this study was to characterize hepatocellular formation of aldehyde-protein adducts during early stages of alcohol-induced liver injury.

Methods: Female Sprague Dawley(R) rats were subjected to the intragastric administration of a low-carbohydrate/high-fat total enteral nutrition diet or a total enteral nutrition diet containing ethanol for a period of 36 days. Indexes of hepatic responses to ethanol were evaluated in terms of changes in plasma alanine aminotransferase activity, hepatic histopathologic analysis, and induction of cytochrome P-4502E1 (CYP2E1). Immunohistochemical methods were used to detect hepatic proteins modified with malondialdehyde (MDA) or 4-hydroxynonenal (4-HNE) for subsequent quantitative image analysis.

Results: After 36 days of treatment, rats receiving the alcohol-containing diet displayed hepatic histopathologies characterized by marked micro- and macrosteatosis associated with only minor inflammation and necrosis. Alcohol administration resulted in a 3-fold elevation of plasma alanine aminotransferase activity and 3-fold increases (p < 0.01) in hepatic CYP2E1 apoprotein and activity. Quantitative immunohistochemical analysis revealed significant (p < 0.01) 5-fold increases in MDA- and 4-HNE modified proteins in liver sections prepared from rats treated with alcohol. The MDA- or 4-HNE modified proteins were contained in hepatocytes displaying intact morphology and were colocalized primarily with microvesicular deposits of lipid. Aldehyde-modified proteins were not prevalent in parenchymal or nonparenchymal cells associated with foci of necrosis or inflammation.

Conclusions: These results suggest that alcohol-induced lipid peroxidation is an early event during alcohol-mediated liver injury and may be a sensitizing event resulting in the production of bioactive aldehydes that have the potential to initiate or propagate ensuing proinflammatory or profibrogenic cellular events.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aldehydes / analysis*
  • Aldehydes / metabolism
  • Animals
  • Apoproteins / analysis*
  • Apoproteins / biosynthesis
  • Ethanol / administration & dosage*
  • Female
  • Immunohistochemistry
  • Liver / chemistry
  • Liver / drug effects*
  • Liver / metabolism
  • Malondialdehyde / analysis*
  • Malondialdehyde / metabolism
  • Rats
  • Rats, Sprague-Dawley


  • Aldehydes
  • Apoproteins
  • Ethanol
  • Malondialdehyde
  • 4-hydroxy-2-nonenal