Effect of chronic alcohol consumption and moderate fat diet on vitamin A status in rats fed either vitamin a or beta-carotene.
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.
D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D006801:Humans; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014801:Vitamin A / Q000378:metabolism*
D004041:Dietary Fats; D008055:Lipids; D014801:Vitamin A; D002338:Carotenoids