ALCOHOL INCREASES PLASMA-LEVELS OF CHOLESTEROL DIET-INDUCED ATHEROGENIC LIPOPROTEINS AND AORTIC ATHEROSCLEROSIS IN RABBITS

The purpose of the present study was to reexamine the relationship bet ween alcohol and atherosclerosis. Two experiments were performed: The first contained three groups of New Zealand White (NZW) female rabbits . The control group was fed a cholesterol-containing liquid diet and t he other two groups were fed the same diet with either 20% or 30% of t he calories supplied by alcohol. The second experiment had two treatme nts: one control group and another group fed a 10% alcohol diet. In ex periment I, alcohol at the 20% and 30% levels increased VLDL and LDL b ut not HDL compared with levels in control rabbits. Hepatic mRNA level s of apolipoprotein (ape) A-I, apoB, and 7 alpha-hydroxylase were not affected by alcohol. However, the LDL-receptor mRNA was decreased to h alf of control values by either 20% or 30% alcohol. Lesion areas and a ortic cholesterols were significantly increased in the 20% and 30% alc ohol-treated groups. Also, significant correlations were found between plasma cholesterol levels and total lesion area or lesion cholesterol contents. In experiment 2, the 10% alcohol-treated rabbits showed no differences in circulating lipoproteins, LDL-receptor mRNA, or lesion formation above that observed in controls. These experiments suggest t hat alcohol substituted at 20% or 30% of the dietary calories induces hypercholesterolemia and more aortic atherosclerotic lesions. The alco hol-induced accumulation of VLDL and LDL was accompanied by low hepati c LDL-receptor mRNA levers, suggesting that alcohol may affect LDL-rec eptor expression and rates of lipoprotein clearance, but more experime nts are needed to evaluate this possibility.