All-trans-retinoic acid inhibits retinol esterification by acyl-CoA: retinol acyltransferase (EC 2.3.1.76) from rat and human small intestinal mucosa.
1. Formation of retinyl esters catalyzed by acyl-CoA:retinol acyltransferase (ARAT; retinol fatty-acyltransferase; EC 2.3.1.76) from intestinal mucosa has been studied in vitro in the presence of all-trans-retinoic acid. 2. The incubation system contained microsomal preparations from the tissue tested, radioactive retinol and palmitoyl-CoA. The product formed was separated from the substrates by chromatography on alumina columns. 3. All-trans-retinoic acid inhibited ARAT both from rat and human intestinal mucosa. 4. Inhibition occurred instantly. At a concentration of retinol of 80 microM, a 50% inhibition was obtained with 50 microM-retinoic acid. 5. The inhibition of ARAT by retinoic acid may be of importance for normal retinol absorption in patients receiving retinoid therapy.
Müller
H
H
Institute for Nutrition Research, University of Oslo, Norway.
Norum
K R
KR
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002384:Catalysis; D004952:Esters; D006801:Humans; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000201:enzymology*; D007421:Intestine, Small / Q000201:enzymology*; D008297:Male; D008861:Microsomes / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D051142:Retinol O-Fatty-Acyltransferase; D014212:Tretinoin / Q000494:pharmacology*
D004952:Esters; D014212:Tretinoin; D000217:Acyltransferases; D051142:Retinol O-Fatty-Acyltransferase