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Validation of dual stable isotope method for measuring cholesterol absorption in hamsters
Author(s) -
Ghanam Khadija,
Wang Yanwen
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.721.9
Subject(s) - cholesterol , absorption (acoustics) , chemistry , isotope , hamster , stable isotope ratio , cholesterol lowering , endocrinology , medicine , chromatography , biology , biochemistry , materials science , physics , quantum mechanics , composite material
Although dual stable isotope method has been used to measuring cholesterol absorption rate in hamsters, this method is adopted from humans and has not been well validated in hamster model. Thus, we have conducted two studies in hamsters to validate this method in terms of optimum time points and effective dose of two cholesterol tracers. After 2 wk of adaptation, male Golden Syrian hamsters were administered orally with 18 O‐cholesterol (0.45 mg in study 1 and 0.6 mg in study 2) and intravenously injected with 13 C‐cholesterol (0.18 mg in study 1 and 0.24 mg in study 2). Blood samples were collected at 0, 6, 24, 48, 72, 96, and 120 h, respectively following the injection. The enrichment of 18 O and 13 C in free cholesterol of red blood cells was analyzed using isotope ratio mass spectrometry (IRMS) and used to calculate cholesterol absorption rate. The results showed that both tracers increased gradually in the first 6 or 24h and gradually declined over next 4 days. The tracers at low and high doses behaved similarly over the time. The ratio of 18 O/ 13 C reached a plateau at 48 h and stayed constant until 96 h. The percent cholesterol absorption rate did not differ among 48, 72 and 96 h. These results suggest that cholesterol absorption rate can be measured precisely using the dual stable isotope method at 48 or 72h with the injection of lower dose of stable isotope. Supported by Atlantic Innovation Fund, Canada