[Studies of 17 beta-hydroxysteroid-dehydrogenase activity in human uterine cervix]

The kinetics of 17 beta-hydroxysteroid-dehydrogenase (17 beta-HSD) activity in the human uterine cervix were determined, as were its localization in cervical tissues and the changes in two phases of the menstrual cycle. The Km value for 17 beta-HSD calculated by a Lineweaver-Burk's plot, was 2.0 microM. The 17 beta-HSD activities in columnar epithelium, squamous epithelium and connective tissue in the proliferative phase were 49.1 +/- 8.9 (p mol/mg protein/hour), 16.5 +/- 2.3, and 9.0 +/- 1.0 (mean +/- SE) (n = 5), respectively. In the secretory phase, the 17 beta-HSD activity in each site was 42.8 +/- 6.6, 12.2 +/- 3.1, and 10.6 +/- 1.6 (n = 6), respectively. Thus, the 17 beta-HSD activity was significantly higher in the columnar epithelium (p less than 0.01) than in the other two sites, but there was no significant difference between the activity in the secretory and proliferative phases during menstruation.