Grummer M A, Erdman J W
J Nutr. 1983 Feb;113(2):350-64. doi: 10.1093/jn/113.2.350.
The effect of chronic alcohol consumption on vitamin A metabolism was investigated in male rats. Liquid diets containing five times the NRC requirement for vitamin A and varied levels of ethanol were fed. The vitamin A content of the liver was decreased in rats receiving alcohol. Liver lipids were only slightly elevated in alcohol-fed rats. Hepatic vitamin A storage was also decreased in rats fed 30% calories as alcohol and beta-carotene or vitamin A at the NRC requirement level, but not in rats fed one-sixth the NRC requirement as vitamin A. The activities of alcohol dehydrogenase, NADPH cytochrome c reductase, and retinol dehydrogenase were not altered in hepatic or testicular tissue by the vitamin A or alcohol content of the diet. When an intragastric dose of [3H]retinyl acetate or [14C]beta-carotene was administered, fecal excretion of radioactivity was lower than controls in rats receiving 30% ethanol in the diet for a total of 4 weeks, for 1 week following 7 weeks of control diet consumption, and after an acute dose of ethanol. Recovery of the 3H label was greater in the testes of rats chronically consuming ethanol. When a solution containing [3H]retinyl acetate or [3H]beta-carotene with or without ethanol was injected into intestinal segments, no alterations in absorption of retinyl acetate or beta-carotene due to ethanol occurred. It is concluded that alcohol consumption results in decreased hepatic vitamin A storage, which is not due to the malabsorption of either retinyl acetate or beta-carotene, or to altered activities of several enzymes involved in ethanol and vitamin A metabolism.
研究了长期饮酒对雄性大鼠维生素A代谢的影响。给大鼠喂食含五倍于美国国家研究委员会（NRC）维生素A需求量且乙醇含量不同的流质饮食。摄入酒精的大鼠肝脏中的维生素A含量降低。喂食酒精的大鼠肝脏脂质仅略有升高。以酒精形式提供30%热量且β-胡萝卜素或维生素A含量为NRC需求量水平的大鼠，其肝脏维生素A储存量也降低，但以维生素A形式提供六分之一NRC需求量的大鼠则未出现这种情况。饮食中的维生素A或酒精含量并未改变肝脏或睾丸组织中乙醇脱氢酶、NADPH细胞色素c还原酶和视黄醇脱氢酶的活性。当给予胃内剂量的[3H]醋酸视黄酯或[14C]β-胡萝卜素时，在饮食中摄入30%乙醇共4周的大鼠、在摄入对照饮食7周后再摄入1周乙醇的大鼠以及给予急性剂量乙醇后，粪便放射性物质排泄量均低于对照组。长期摄入乙醇的大鼠睾丸中3H标记物的回收率更高。当将含或不含乙醇的[3H]醋酸视黄酯或[3H]β-胡萝卜素溶液注入肠段时，未发现乙醇对醋酸视黄酯或β-胡萝卜素的吸收有影响。研究得出结论，饮酒导致肝脏维生素A储存量降低，这并非由于醋酸视黄酯或β-胡萝卜素吸收不良，也不是由于参与乙醇和维生素A代谢的几种酶的活性改变所致。
