Influence of dietary ascorbic acid on cholesterol 7 alpha-hydroxylase activity in the rat.
An experiment was carried out to determine whether dietary excess of ascorbic acid inhibits cholesterol 7 alpha-hydroxylase activity and elevates cholesterol levels in the rat, as previously observed in the guinea pig. Male, weanling Sprague-Dawley rats were fed a cereal-based diet supplemented with 0, 0.5, 10.0, or 20.0 g ascorbate/kg for 45 days. Ascorbate supplementation did not alter plasma ascorbate levels in the rat, but did increase hepatic ascorbate at the highest dietary intakes (10.0 and 20.0 g ascorbate/kg diet). Ascorbate supplementation had no effect upon plasma and liver cholesterol levels or cholesterol 7 alpha-hydroxylase activity. Under the experimental conditions employed, the rat appears resistant to ascorbate-induced alteration of sterol metabolism.
D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013250:Steroid Hydroxylases / Q000378:metabolism*
D002784:Cholesterol; D013250:Steroid Hydroxylases; D002790:Cholesterol 7-alpha-Hydroxylase; D001205:Ascorbic Acid