title: The presence of 17 beta-hydroxysteroid dehydrogenase activity in preimplantation rat and mouse blastocysts.
abstract: When Day 5 rat blastocysts and Day 4 and 5 mouse blastocysts were cultured in 53 microliters 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 17 beta-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 17 beta-hydroxysteroid dehydrogenase.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001755:Blastocyst / Q000201:enzymology*; D004958:Estradiol / Q000378:metabolism; D004970:Estrone / Q000096:biosynthesis; D005260:Female; D007700:Kinetics; D051379:Mice; D011247:Pregnancy; D051381:Rats
chemical_list: D004970:Estrone; D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases; C032690:3-alpha-(17-beta)-hydroxysteroid dehydrogenase (NAD(+))