Journal of Lipid Research, Vol 17, 220-230, Copyright © 1976 by Lipid Research, Inc.
Isolation, characterization, and biological activity of retinyl phosphate from hamster intestinal epithelium
JP Frot-Coutaz, CS Silverman-Jones and LM De Luca
Epithelial cells from hamster small intestine, in short term culture,
incorporated [carbinol-14C]retinol into a compound that is identical to
synthetic retinyl phosphate, as judged by chromatography on DEAE-
cellulose, silicic acid, and thin layers of silica gel. The biological
compound displays the same absorption spectrum as does synthetic retinyl
phosphate with a maximum at 325 nm. Hydrolysis with mild alkali yields
anhydroretinol, as it does for synthetic retinyl phosphate, with absorption
maxima at 388, 368, and 346 nm. Enzymic hydrolysis by alkaline phosphatase
releases 9% of the radioactivity as [14C]retinol. Under the same
conditions, 9% of synthetic retinyl phosphate is hydrolyzed to retinol. The
biological compound was tested for biological activity. At a concentration
of 5.5 x 10-8 M it was as active as retinol and retinyl phosphate in
reversing keratinization induced in hamster tracheal epithelium by vitamin
A deficiency. It is concluded that hamster intestinal cells synthesize
retinyl phosphate.