Metabolism of all-trans-retinyl acetate to retinoic acid in hamster tracheal organ culture

All-trans-[³H]retinyl acetate has been shown to be metabolized to all-trans-[³H]retinoic acid in a target tissue of vitamin A action, the hamster trachea in organ culture. That the compound produced is indeed all-trans-retinoic acid is demonstrated by chromatography of the biosynthetically produced retinoic acid with synthetic all-trans-retinoic acid in two different high-pressure liquid chromatographic systems, either as the free acids in a reverse-phase system or as the methyl esters in a normal-phase system. The all-trans-[³H]retinoic acid was also found in the tracheal epithelium and cartilage as well as in the medium. In addition the tracheal tissue also contained retinyl palmitate and other esters. Finally, further in vitro metabolism of [³H]retinyl acetate paralleled the metabolism of [³C]retinoic acid suggesting that these two compounds are being metabolized through similar pathways.