The presence of 17β-hydroxysteroid dehydrogenase activity in preimplantation rat and mouse blastocysts

Publisher Website
Google Scholar
Abstract
When Day 5 rat blastocysts and Day 4 and 5 mouse blastocysts were cultured in 53 μl of medium containing 1340 or 2680 pg [3H]estradiol (E2), large amounts of [3H]estrone (E1) were detected in the medium at daily intervals for up to 5 days. This indicates the presence of 17β-hydroxysteroid dehydrogenase in the embryos. The activity was higher at a higher concentration of E2 and was also higher in mouse than in rat blastocysts. In the mouse, the activity was higher in Day 5 than Day 4 blastocysts during the first day in culture; then it decreased in Day 5 but increased in Day 4 blastocysts. The importance of E2 in embryonic development and implantation as suggested by others may be related to the activity of 17β-hydroxysteroid dehydrogenase.