17β-Hydroxysteroid dehydrogenase activity in uterine cervix of normal subjects and carcinoma patients.

The ability of the human normal uterine cervix and cervical carcinoma to interconvert estradiol-17β and estrone is due to the activity of 17β-hydroxysteroid dehydrogenase (17β-HSD). Human cervical 800 x g supernatant fractions were analyzed by incubating with 3H-estradiol (20 nM) and NAD (0.25 ตmol) in 50 mM Tris buffer at pH 8.0. The incubation was terminated by adding 1 ml of 100% methanol and the supernatants were evaporated in air. The dry residues were resuspended in methanol, and aliquots were chromatographed in silica gel thin layer plates in benzene : ethanol (9 : 1, V : V). The 17β-HSD activity was determined from the amount of estrone formed and expressed as nanomoles of estrone formed/mg protein X h. The 17β-HSD activity was higher in normal cervix than in cervical carcinoma. Estradiol-17β added to incabation mixture caused a slight increase in enzyme activity only in cervical carcinoma while it had no effect in normal tissues. Progesterone administration increased 17β-HSD activity in some cases of normal and carcinoma cervix. These results suggest that changes in enzyme concentrations may play a physiologic role in the regulation of tissue levels of estradiol-17β.