title: Unusual product ratios resulting from the gamma-irradiation of cholesterol in liposomes.
abstract: Cholesterol in aqueous suspensions of multilamellar vesicles (MLV) was exposed to gamma-irradiation (0.5-10 kGy) at 0-4 degrees C. Cholesterol oxidation products resulting from the irradiation were isolated by dry column extraction followed by preparative thin-layer chromatography (TLC) and were quantitated by on-column gas chromatography (GC). The ratio of 7-ketocholesterol/cholesterol 5,6-epoxides generated by irradiation was less than one, much lower than the ratio of ten commonly produced by autoxidation. Irradiation also produced relatively higher amounts of 7-hydroxycholesterol than did autoxidation. These unique product ratios may be suitable indicators of past exposure to irradiation.
authors.affiliation: U.S. Department of Agriculture, Eastern Regional Research Center, Philadelphia, Pennsylvania 19118.
authors.forename: G
authors.initials: G
authors.lastname: Maerker
authors.forename: K C
authors.initials: KC
authors.lastname: Jones
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol / Q000737:chemistry / Q000528:radiation effects*; D005720:Gamma Rays; D008081:Liposomes; D010084:Oxidation-Reduction; D010710:Phosphates / Q000032:analysis; D010715:Phosphatidylglycerols
chemical_list: D008081:Liposomes; D010710:Phosphates; D010715:Phosphatidylglycerols; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol; C030345:1,2-dipalmitoylphosphatidylglycerol