STABILIGEN

STABILIGEN was created in 1985 and is specialized in induction and inhibition enzymatic studies linked to the cytochrome P450 3A4. For these studies, STABILIGEN has developed an urinary 6β-hydroxycortisol assay. This in vivo human test allows the measurement of one liver enzyme activity responsible for drug metabolism. As none of the enzyme activities are directly measurable in biological fluids, indirect tests based on the measurement of endogenous and exogenous substrates have been developed. The cytochrome P450 3A4 (CYP 3A4) is responsible for the conversion of cortisol into 6β-hydroxycortisol. This explains that the urinary excretion of 6ß-hydroxycortisol thus reflects the liver activity of CYP 3A4.