title: Enzymatic oxidation of all-trans retinal to retinoic acid in rat tissues.
abstract: The 100,000 x g supernatant (cytosolic) fraction of rat tissue homogenates catalyzes the oxidation of all-trans retinal to retinoic acid. Kidney, testis, and lung were the most active of the tissues examined. The presence of enzyme activity in liver and intestine could be detected only when a substrate concentration beyond the saturation point for retinal reductase was used. Spleen, brain, and plasma had no activity. Boiled supernatants did not catalyze the reaction. The enzymatic product was chemically and physically identified as retinoic acid. The cytosol of kidney tissue also catalyzed the conversion of retinol to retinoic acid. These data indicate that kidney tissue has the highest retinal oxidase activity and suggest that it may play a major role in the oxidative metabolism of retinol in the body.
authors.affiliation: Department of Medicine, Université de Montréal, Que., Canada.
authors.forename: P V
authors.initials: PV
authors.lastname: Bhat
authors.forename: L
authors.initials: L
authors.lastname: Poissant
authors.forename: P
authors.initials: P
authors.lastname: Falardeau
authors.forename: A
authors.initials: A
authors.lastname: Lacroix
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008745:Methylation; D010084:Oxidation-Reduction; D051381:Rats; D050697:Retinal Dehydrogenase; D012172:Retinaldehyde / Q000378:metabolism*; D012176:Retinoids / Q000378:metabolism*; D014212:Tretinoin / Q000378:metabolism*
chemical_list: D012176:Retinoids; D014212:Tretinoin; D000445:Aldehyde Oxidoreductases; D050697:Retinal Dehydrogenase; D012172:Retinaldehyde