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Published on: August 23, 2019
A comparison of 4β-hydroxycholesterol : cholesterol and 6β-hydroxycortisol : cortisol as markers of CYP3A4 induction
Yvonne Mårde Arrhén1, Hanna Nylén, Anita Lövgren-Sandblom
1Clinical Chemistry, Karolinska University Hospital, Huddinge, Sweden.
Aim:
To compare plasma 4β-hydroxycholesterol : cholesterol with urinary 6β-hydroxycortisol : cortisol as markers of cytochrome P4503A4 activity before and after treatment with rifampicin for 2 weeks.
Method:
6β-hydroxycortisol and cortisol were determined by liquid chromatography tandem mass spectrometry and 4β-hydroxycholesterol was determined by gas chromatography-mass spectrometry in three groups of healthy volunteers.
Results:
Induction ratios for 6β-hydroxycortisol : cortisol were 1.8, 3.9 and 4.5 for 20 mg day(-1) , 100 mg day(-1) or 500 mg day(-1) of rifampicin, respectively. The corresponding ratios for 4β-hydroxycholesterol : cholesterol were 1.5, 2.4 and 3.8.
Conclusions:
Plasma 4β-hydroxycholesterol : cholesterol gave similar induction ratios to urinary 6β-hydroxycortisol : cortisol.
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