Progesterone catabolizing enzyme, the enzyme 20α-hydroxysteroid dehydrgenase(20α-HSD) is pivotal in the regulation of ovarian function in rodents, which catabolizes progesterone into biologically inactive 20α-hydroxypregn-4-en-3-one(20α-OHP). In this study was carried out the influence of 20α-HSD activity of ovarian function, we investigated changes in ovarian cytosol 20α-HSD activity and serume progesterone concentration during the estrous cycles and pregnancy in rat. During the estrous cycles, the 20α-HSD activities were highest on the progestrous, but serum progesterone concentration was lowest on this phase. During the pregnancy, the 20α-HSD activities were relatively higher early pregnancy(day-1-3 gestation) and late pregnancy(day 21 to parturition), senum progesterone concentration was maintained significantly high to day 19 of gestation. The 20α-HSD activities were Dower during the middle pregnancy.
From these results, ovarian 20α-HSD activities may possibly act as physiologically very important in the control and maintenance of estrous cycles in rat.
|