Divergent effects of excess dietary vitamin A on alimentary cholesterolemia in cockerels of different genetic backgrounds.
The variable effect of excessive vitamin A intake on alimentary cholesterolemia was investigated in cockerels of strains of White Leghorns and New Hampshires. With the New Hampshire cockerels, the feeding of 0.5% of dietary cholesterol resulted in greater cholesterolemia when the diet contained 1700 I.U. of vitamin A per kilogram than when it contained 22000 I.U. of vitamin A per kilogram. With the White Leghorn cockerels, on the other hand, cholesterolemia was enhanced with the higher level of dietary vitamin A. Absorption of a single oral dose of cholesterol was increased in birds of both breeds when vitamin A had been given previously by injection. In the White Leghorn cockerels the percentage of newly absorbed cholesterol in the hepatic pool was reduced by vitamin A administration, whereas in the New Hampshire cockerels the percentage was increased. It was concluded that excess vitamin A may have divergent effects on alimentary cholesterolemia in chickens of different genetic backgrounds as a result of opposite effects on the liver-blood ratio of a large load of cholesterol.
D000818:Animals; D002645:Chickens; D002784:Cholesterol / Q000097:blood*; D004032:Diet; D006986:Hypervitaminosis A; D007408:Intestinal Absorption; D008099:Liver / Q000378:metabolism; D008297:Male; D008967:Molecular Biology; D014801:Vitamin A / Q000378:metabolism
D014801:Vitamin A; D002784:Cholesterol