| Abstract
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The effect of dietary ethanol on atherosclerotic regression and vasoconstriction in atherosclerotic rabbits was addressed by feeding male New Zealand white rabbits (n = 19) a diet enriched with 0.8% cholesterol for 45 days, followed by randomization to one of three diets for the next 45 days: (1) Continued consumption of a cholesterol-rich diet (CC; n = 6), (2) Consumption of a cholesterol-free diet (CF; n = 6), and (3) Consumption of a cholesterol-free diet supplemented with ethanol in the drinking water (10% v/v; ECF; n = 7). Atherosclerosis and vasoconstrictive properties of the aortas were evaluated on day 90. Data are expressed as mean SEM, means with the same letter are not significantly (P < 0.05) different. Total plasma cholesterol of the CC, CF and ECF groups were 1532 107.01A, 440.50 44.08B and 957.79 157.21 mg/dl', respectively. Plasma triglyceride concentrations of the CC, CF and ECF groups were 238.97 64.28A, 79.97 11.77A and 433.32 122.07B mg/dl, respectively. No significant differences were noted in regards to the percent of aortic surface covered by Sudan-IV staining lesions, fatty streak areas in aortic cross-sections, smooth muscle area or aortic cholesterol content. Neither the CF nor the ECF diets promoted atherosclerotic regression. The total liver cholesterol content of the CC, CF and ECF groups were 3.98 0.33A, 2.36 0.30B and 1.97 0.31B grams cholesterol/liver, respectively. Norepinephrine (10M) promoted maximal contractile forces in the CC, CF and ECF groups of 3.69 0.32A, 5.09 0.39B and 5.31 0.30B grams, respectively. Potassium chloride (80 mM) promoted maximal contractile forces in the CC, CF and ECF groups of 4.01 0.35A, 5.04 0.38B and 5.34 0.47 gramsB respectively. The contractile forces developed in response to 200 mg/dl ethanol by the CC, CF and ECF groups were 51.4 7.5A, 71.2 12.6A and 104.9 31.5A, respectively. Serotonin (10M) developed contractile forces in the CC, CF and ECF groups of 2.35 0.24A, 2.13 0.21A and 2.89 0.59A grams, respectively. This investigation demonstrated that the inclusion of dietary ethanol as part of a lipid lowering diet in atherosclerotic rabbits is associated with the maintenance of risk factors promoting with vasospasm and continued atherogenesis.
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