The effect of ethanol on glycerolipid biosynthesis by primary monolayer cultures of adult rat hepatocytes.

This study evaluates the effects of ethanol exposure on glycerolipid production and release by hepatocyte monolayers. Glycerolipid formation from [1,3-14C]glycerol was increased in monolayers exposed to ethanol (1--50 mM) for 6 h. Monolayers exposed to 1 mM ethanol for 24 h also exhibited a rise in glycerolipid formation from either [1,3-14C]glycerol or [1-14C]palmitate; however, higher ethanol concentrations produced a dose dependent decrease in glycerolipid formation. Glycerolipids released into the medium by monolayers declined after all periods of ethanol exposure. The effects of ethanol on the enzymatic reactions involved in glycerolipid biosynthesis were determined in homogenates prepared from monolayers exposed to ethanol. Two enzymes, phosphatidate phosphohydrolase and glycerol kinase, exhibited ethanol-induced alterations in enzyme activity; however, only glycerol kinase activity correlated well with monolayer glycerolipid formation. These ethanol-induced alterations in enzyme activities and glycerolipid biosynthesis were reduced by simultaneously exposing monolayers to pyrazole or cycloheximide.