Effect of l-carnitine on liver cell membranes in ethanol-intoxicated rats

Ethanol intoxication is characterized by changes in cell metabolism which alter the structure and function of cell membrane components, including phospholipids and integral membrane proteins. The interaction of food nutrients with ethanol may modulate alcohol toxicity. One such compound is l-carnitine (l-3-hydroxy-4-N,N,N-trimethylaminobutyrate), which is also an antioxidant. Here we investigate l-carnitine as an antioxidant and assess its effect on the composition and electrical charge of liver cell membranes in ethanol-intoxicated rats. Qualitative and quantitative phospholipid composition and the presence of integral membrane proteins were determined by high performance liquid chromatography (HPLC). Electrophoresis was used to determine the surface charge density of the rat liver cell membranes. Ethanol increased phospholipid levels and altered the level of integral proteins as determined by decreased phenylalanine (Phe), cysteine (Cys) and lysine (Lys). Ethanol significantly enhanced changes in the surface charge density of the liver cell membranes. l-Carnitine administration to ethanol-intoxicated rats significantly protects phospholipids and proteins against oxidative modifications. Therefore, the beneficial effect of l-carnitine may be connected to its ability to scavenge free radicals.