%0 Journal Article %T Demethylation capacity of human fetal adrenal mitochondrial cytochrome P-450 in vitro. %A Wang Hui %A Peng Ren-xiu %A Zhang Yan-hua %A Chen Jin-he %A Li Qi-xiong %A Kong Rui %A Ding Hong %J Acta Pharmacologica Sinica %D 2016 %B 2016 %9 %! Demethylation capacity of human fetal adrenal mitochondrial cytochrome P-450 in vitro. %K %X AIM: To explore the capacity and characteristics of adrenal mitochondria to metabolize xenobiotics in vitro in human fetus. METHODS: Subcellular fractions of fetal adrenal were prepared by differential centrifugation. Mitochondrial P-450 system was proved by spectral analyses and SDS-PAGE. The formaldehyde formation contents were measured with Nash reagent. RESULTS: The erythromycin N-demethylation linearly increased in the protein concentration (1-4 mg)- and incubation time (10-30 min)-dependent manners. A typical concentration-effect relationship appeared with erythromycin 0.067-1 mmol.L-1 and a positive correlation (r = 0.641, P 0.05), 162% (P < 0.01), and 62% (P < 0.01), respectively, of those in microsomes. There was correlation between mitochondria and microsomes in the N-demethylation of erythromycin (r = 0.708, P < 0.05) and benzfetamine (r = 0.707, P < 0.05). Troleandomycin stimulated erythromycin N-demethylation in adrenal mitochondria as well as in adrenal and liver microsomes in vitro. CONCLUSION: Fetal adrenal mitochondria, with multiple P-450 isoforms and greater capacity of demethylation, play a role in drug-metabolism during fetal development. %U http://www.chinaphar.com/article/view/7653 %V 20 %N 4 %P 358-362 %@ 1745-7254