Portal de Periódicos da CAPES

AN IN VITRO ASSAY FOR ESTRADIOL-17/3 AND ESTRONE1

1956; Oxford University Press; Volume: 58; Issue: 2 Linguagem: Inglês

10.1210/endo-58-2-150

1945-7170

Edwin E. Gordon, Claude A. Villee,

Steroid Chemistry and Biochemistry

ESTRADIOL-17β2 added in vitro has been shown to stimulate a reaction mediated by a diphosphopyridine nucleotide (DPN) dependent isocitric dehydrogenase in human, term placental extracts (Villee, 1955; Villee and Gordon, 1955). In the course of this reaction, DPN is reduced to DPNH and the product can be measured by its absorption of light at 340 mμ. in a spectrophotometer (Gordon and Villee, 1955). In this paper, the rate of DPN reduction is shown to be a function of the concentration of estradiol in the incubation medium. Estrone is as effective as estradiol in this reaction, but none of a number of other steroids tested has this marked stimulatory property. These circumstances provide the basis for a sensitive, in vitro method for measuring estradiol and estrone. Data are presented which compare the analyses of urine extracts by this method of estrogen determination with those of bioassay by the vaginal smear response in adult castrate rats (Smith and Smith, 1952). Kinetic analysis of the data is compatible with the hypothesis that estradiol functions to activate the DPN dependent isocitric dehydrogenase.