کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1911479 | 1046819 | 2007 | 7 صفحه PDF | دانلود رایگان |
The oxysterols 7β-hydroxycholesterol and 7-ketocholesterol are cholesterol autoxidation products. These two oxysterols are formed as a result of low density lipoprotein oxidation and in a study on biomarkers for oxidative stress in patients with atherosclerosis, 7β-hydroxycholesterol was found to be the strongest predictor of progression of carotid atherosclerosis. Interconversion of 7β-hydroxycholesterol and 7-ketocholesterol in vitro has been reported recently, using recombinant 11β-hydroxysteroid dehydrogenase or rodent liver microsomes. In this study deuterium-labeled 7β-hydroxycholesterol or 7-ketocholesterol was administered intravenously to two healthy volunteers and blood samples were collected at different time points. The mean half-life for elimination of 7β-hydroxycholesterol from the circulation was estimated to be 1.9 h. The corresponding half-life for 7-ketocholesterol was estimated to be 1.5 h. Infusion of deuterium-labeled 7-ketocholesterol resulted in labeling of 7β-hydroxycholesterol and vice versa. In addition, the biological within-day and between-day variations of the two oxysterols were determined. In summary, the present investigation clearly shows an interconversion of 7β-hydroxycholesterol and 7-ketocholesterol in humans.
Journal: Free Radical Biology and Medicine - Volume 43, Issue 5, 1 September 2007, Pages 695–701