Metabolism of cryptoxanthin in freshwater fish.
In search of other provitamins A, the metabolism of cryptoxanthin was studied in several species of freshwater fish, i.e. Channa gachua, Labeo boga (retinol-rich) and Heteropneustes fossilis (dehydroretinol-rich). The fish were either allowed to starve for 20-25 d to make their intestines free from carotenoids and vitamin A or kept on a vitamin-A-deficient diet for 140-150 d to deplete the initial reserve of vitamin A in the livers. Retinol-rich freshwater fish such as C. gachua and L. boga converted cryptoxanthin into retinol and no 3-dehydroretinol or 3-hydroxyretinol could be isolated from those fish that received cryptoxanthin. 3-Hydroxyretinol and 3-dehydroretinol were isolated from the vitamin-A-deficient H. fossilis, a 3-dehydroretinol-rich freshwater siluroid, after the administration of cryptoxanthin.
D000818:Animals; D002338:Carotenoids / Q000031:analogs & derivatives* / Q000378:metabolism; D065366:Cryptoxanthins; D005399:Fishes / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D014801:Vitamin A / Q000031:analogs & derivatives / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000378:metabolism; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives*
D065366:Cryptoxanthins; D024341:Xanthophylls; D019207:beta Carotene; C024366:vitamin A2; D014801:Vitamin A; D002338:Carotenoids; C015943:3-hydroxyretinol