The uptake of dietary polyprenols and their modification to active dolichols by the rat liver.
The uptake of dietary polyprenols was studied by administering, through a gastric tube, labeled alpha-saturated and alpha-unsaturated polyprenols, with 11 and 19 isoprene residues. The lipids appeared in all organs but mostly in the liver after 16 h where those with 11 isoprenes were in much higher concentration than the prenols with 19 isoprene residues; the distribution in the liver was studied in detail. About 45% of the polyprenols taken up were esterified with fatty acids. A part of the radioactivity (6-30%) appeared in the supernatant but mostly in water-soluble form. Among subcellular fractions, the highest uptake was found in the outer mitochondrial membranes. After 16 h, both 11- and 19-residue alpha-unsaturated injected prenols were present to a large extent as alpha-saturated compounds in liver homogenates and subcellular fractions. About 10-15% of the lipids were phosphorylated. The results suggest that a part of the dolichol phosphate pool, participating in glycosylation reactions, may derive from dietary unsaturated polyprenols which after uptake can be reduced and phosphorylated.
D000818:Animals; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D004032:Diet; D004224:Diterpenes / Q000378:metabolism*; D004286:Dolichols / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D013729:Terpenes / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution
D004224:Diterpenes; D004286:Dolichols; D013729:Terpenes; C017788:undecaprenol