Metabolism and biological potency of retro-retinyl acetate in the rat.
1. retro-Retinyl acetate was shown to exert its biological activity by conversion into vitamin A. 2. When administered orally, retro-retinyl acetate was hydrolysed to retro-retinol in the intestine, isomerized to retinol and esterified before being transported to the liver for storage. 3. Administration of the compound at as high a dose as 4.0mg./day for 4 days led to the accumulation of both vitamin A and retro-vitamin A in the liver. The amount of retro-vitamin A in liver gradually decreased until it was almost completely converted into vitamin A in 18 days. 4. Intraperitoneal administration of the compound led to the accumulation of both vitamin A and retro-vitamin A in liver and other tissues. No vitamin A was detected in any tissue of rats receiving retro-retinyl acetate intraperitoneally after enterectomy. 5. The small intestine is the major site of conversion of retro-vitamin A into vitamin A. The conversion could also be demonstrated by everted intestinal sacs. 6. The biological potency of retro-retinyl acetate determined by the rat-growth assay was 20.5% that of all-trans-retinyl acetate, when given orally.
D000085:Acetates / Q000378:metabolism*; D000818:Animals; D001681:Biological Assay; D055598:Chemical Phenomena; D002621:Chemistry; D002845:Chromatography; D046508:Culture Techniques; D007274:Injections, Intraperitoneal; D007422:Intestines / Q000032:analysis; D007668:Kidney / Q000032:analysis; D008099:Liver / Q000032:analysis; D008168:Lung / Q000032:analysis; D008297:Male; D051381:Rats; D013053:Spectrophotometry; D013154:Spleen / Q000032:analysis; D013270:Stomach / Q000032:analysis; D014020:Tissue Extracts; D014801:Vitamin A / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000378:metabolism
D000085:Acetates; D014020:Tissue Extracts; D014801:Vitamin A