title: Cytochrome P450 3As gene expression and testosterone 6 beta-hydroxylase activity in human fetal membranes and placenta at full term.
abstract: Expression levels of cytochrome P450 (CYP) 3A4, CYP3A5 and CYP3A7 mRNAs in placentas and fetal membranes, which were split into amnion and chorion leave attached decidua (chorion/decidua), obtained from pregnant women with normal delivery (5 subjects) and Caesarean section (15 subjects) were determined. These CYP3A mRNAs were also expressed in amnion and chorion/decidua together with placenta, although the expression level of these mRNAs was strikingly different between subjects. The expression level of the CYP3A4 mRNA in the placenta was about 2-fold higher than those in amnion and chorion/decidua. On the other hand, the expression levels of CYP3A5 and CYP3A7 mRNAs were highest in chorion/decidua. The immunologically related protein(s) with CYP3A7 was detected in all tissues examined. Testosterone 6beta-hydroxylase activity in homogenate of human placenta, amnion and chorion/decidua were 26.6, 3.7 and 4.6 pmol/h/mg protein, respectively. These results suggest that CYP3As in fetal membranes have the metabolic function to protect the fetus from exposure to drugs.
authors.affiliation: Department of Pharmacy, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Maezawa
authors.forename: Tamihide
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Takashi
authors.initials: T
authors.lastname: Takezawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Kanai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohira
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohmori
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis* / Q000235:genetics; D051544:Cytochrome P-450 CYP3A / Q000096:biosynthesis* / Q000235:genetics; D004789:Enzyme Activation / Q000235:genetics; D005321:Extraembryonic Membranes / Q000201:enzymology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007231:Infant, Newborn; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis / Q000235:genetics; D013250:Steroid Hydroxylases / Q000378:metabolism*; D047929:Term Birth / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D011257:Pregnancy Proteins; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C510164:CYP3A5 protein, human; C103123:CYP3A7 protein, human; D051544:Cytochrome P-450 CYP3A; C022657:steroid hormone 6-beta-hydroxylase; C510163:CYP3A4 protein, human