Alcohol-dependent liver disease (ALD) is a major public health problem since 75% of all medical deaths associated with alcoholism are attributable to cirrhosis. Unfortunately, the effective treatment and prevention and ALD is limited since the mechanisms by which alcohol induces liver cell necrosis are unresolved. Resolution of this issue would be facilitated by the development of an in vitro liver cell model that mimics the hepatocyte's response to ethanol in vivo such as steatosis and necrosis. Therefore, the primary objectives of these studies are to demonstrate that: 1) primary cultures of adult rat hepatocytes incubated (1 to 14 days) with ethanol (10 to 100mM) are an appropriate model in vitro for determining the mechanisms by which ethanol induces liver cell necrosis; 2) ethanol metabolism creates an """"""""oxidative stress"""""""" in liver cells that results in membrane injury when membrane phosphatidylcholines (PC) are peroxidized and then hydrolyzed by phospholipases (PC depletion); 3) ethanol-dependent membrane injury (PC depletion) is reversible, or irreversible, depending on whether membrane PC biosynthesis is, or not, correspondingly increased. The validity of these concepts will be established by incubating cultured hepatocytes with ethanol and agents and increased (linoleate) or decrease (4-methylpyrazole and Vitamin E) ethanol-dependent liver cell injury in vivo and determining the agent mediated changes in ethanol-dependent liver cell injury and the peroxidation, hydrolysis and biosynthesis of membrane PC. Isocaloric (ethanol or carbohydrate) liquid diets will also be acutely and chronically administered to rate to demonstrate that a alcohol-dependent changes in liver cell functions (viability and the peroxidation, hydrolysis and biosynthesis of membrane PC) in cultured hepatocytes are consistent with those observed in the intact animal. In summary, these studies will demonstrate that the peroxidation, hydrolysis and biosynthesis of membrane PC are critical events in ethanol- dependent cell injury. Determining how ethanol and/or other agents such as linoleate and Vitamin E alter membrane PC peroxidation, hydrolysis and biosynthesis will contribute to a better understanding of how to prevent and treat ethanol-induced liver cell injury.
