Specific 5 alpha-dihydrotestosterone receptor and 5 alpha-reductase activity in human amniotic fluid cells.
A macromolecular component which specifically binds tritium-labeled-dihydrotestosterone is present in cultured amniotic fluid cells. The androgen-binding complex is characterized by a 3.6S sedimentation coefficient, an apparent dissociation constant of 1 nmol/L, a mean binding capacity of 243 +/- 140 fmol/mg of DNA, and a specificity for testosterone and dihydrotestosterone. Similar properties have been reported for the androgen receptor of the fetal genital skin fibroblast, which suggests that the tritium-labeled-dihydrotestosterone-binding component in amniotic fluid cells is the androgen receptor. Amniotic fluid cell monolayers incubated with serum-free medium containing testosterone are able to transform testosterone into dihydrotestosterone. The 5 alpha-reduced product has been characterized by thin-layer chromatography and capillary column gas-liquid chromatography. Androgen receptors and 5 alpha-reductase activity are expressed in amniotic fluid cells. The prenatal diagnosis of 5 alpha-reductase deficiency or complete androgen insensitivity syndrome (testicular feminization) is thus theoretically possible and obviously prenatal testing would be indicated in the family at high risk.
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000032:analysis*; D000653:Amniotic Fluid / Q000032:analysis* / Q000166:cytology; D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D002849:Chromatography, Gas; D013196:Dihydrotestosterone / Q000032:analysis*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D006801:Humans; D010088:Oxidoreductases / Q000032:analysis*; D011944:Receptors, Androgen / Q000032:analysis*; D011987:Receptors, Steroid / Q000032:analysis*
D012739:Gonadal Steroid Hormones; D011944:Receptors, Androgen; D011987:Receptors, Steroid; D013196:Dihydrotestosterone; D010088:Oxidoreductases; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase