Changes in the 17 beta-hydroxysteroid dehydrogenase activity of mouse blastocysts during delayed implantation
Authors
Wu, J. T.UMass Chan Affiliations
Department of Obstetrics and GynecologyDocument Type
Journal ArticlePublication Date
1988-12-01Keywords
17-Hydroxysteroid DehydrogenasesAnimals
Blastocyst
Culture Techniques
*Embryo Implantation
*Embryo Implantation, Delayed
Female
Mice
Pregnancy
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
The rate of estrone (E1)----estradiol-17 beta (E2) or E2----E1 conversion catalyzed by 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity was determined for each mouse embryo in modified F-10 medium containing 0.95 microM 3H-E1 or 3H-E2. During delayed implantation, the E1----E2 conversion rate was decreased (p less than 0.005) from 5.69 +/- 0.34 fmol/h/blastocyst on Day 5 to 3.50 +/- 0.46 fmol/h/blastocyst on Day 9, whereas E2----E1 was increased (p less than 0.005) from 7.44 +/- 1.08 to 18.60 +/- 2.04 fmol/h/blastocyst. After estrogen injection, the Day 9 implanting blastocyst showed an increase (p less than 0.005) in E1----E2 conversion to 9.05 +/- 0.64 fmol/h/blastocyst but a slight, insignificant decrease in E2----E1 conversion to 14.2 +/- 1.82 fmol/h/blastocyst. A similar trend was also observed in Day 5 implanting blastocysts when compared to Day 5 delayed blastocysts. Thus, 17 beta-HSD activity in delayed blastocysts favors E2----E1 over E1----E2 conversion in a ratio of 5:1. After estrogen induction of implantation, the E1----E2 conversion rate is stimulated and the ratio of E2----E1 to E1----E2 rate is decreased to 1.5:1. The results suggest that 17 beta-HSD activity may be involved in blastocyst implantation.Source
Biol Reprod. 1988 Dec;39(5):1021-6.