title: Sequential microanalyses of free dolichol, dolichyl fatty acid ester and dolichyl phosphate levels in human serum.
abstract: Sequential microanalyses of free dolichol, dolichyl fatty acid ester and dolichyl phosphate in human serum were made. To determine the level of each dolichol, samples were pretreated using three different methods prior to fluorescent derivatization. To estimate the concentrations of free dolichol, samples were added to alkaline methanol and kept at room temperature for 1 h. In case of dolichyl fatty acid ester, samples were saponified at 100 degrees C for 1 h. To estimate dolichyl phosphate, saponified lipid extracts were treated with acid phosphatase. Each pretreated dolichol was reacted with anthracene-9-carboxylic acid and amounts of 9-anthroyl derivatives were determined fluorometrically by HPLC. This method is simple and three types of dolichols can be estimated using the same HPLC system. This analysis is also sufficiently sensitive for measurement of serum dolichol levels. The contents of free dolichol, dolichyl fatty acid ester and dolichyl phosphate in human serum were found to be 44.9 +/- 10.5 ng/ml (n = 32), 76.4 +/- 24.2 ng/ml (n = 32) and 43.5 +/- 15.1 ng/ml (n = 13), respectively. These levels had apparently no correlation to age or serum total cholesterols. A linear correlation between dolichols and high-density lipoprotein cholesterols reflects the fact that the dolichols are associated with the high-density lipoprotein fraction.
authors.affiliation: Division of Clinical Biochemistry, National Medical Center, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Yasugi
authors.forename: M
authors.initials: M
authors.lastname: Oshima
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004288:Dolichol Phosphates / Q000097:blood*; D004286:Dolichols / Q000031:analogs & derivatives* / Q000097:blood*; D004952:Esters / Q000097:blood*; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood
chemical_list: D004288:Dolichol Phosphates; D004286:Dolichols; D004952:Esters; D008075:Lipoproteins, HDL; C028306:dolichol monophosphate