A possible role of progesterone receptor in mouse oocyte in vitro fertilization regulated by norethisterone and its reduced metabolite.
BACKGROUND
The contraceptive effect of the progestogen norethisterone (NET) and its main metabolites 5alpha-NET and 3beta,5alpha-NET has been demonstrated in several species, and most studies have focused on the effects of these compounds in the uterus. We previously reported that 5alpha-NET inhibits the progesterone (P(4))-induced acrosome reaction in pig and mouse spermatozoa and induces severe morphological damage in two-cell fertilized mouse oocytes.


METHODS
The main goal of this study was to analyze the possible role of P(4) receptor (PR) in the effects of NET and 5alpha-NET on the oocyte fertilization process. Different steroid treatments were used with or without cumulus-enclosed oocytes.


RESULTS
It was demonstrated that NET increases the percentage of fertilized oocytes in the same manner as P(4) does, while 5alpha-NET reduces the percentage of fertilized oocytes. This effect was not reversed by P(4) in the same concentrations.


CONCLUSIONS
A possible molecular mechanism for the effects of 5alpha-NET may be through a PR localized in the oocyte plasma membrane.
Flores-Herrera
Héctor
H
Departamento de Investigación Biomédica, Instituto Nacional de Perinatología, Isidro Espinoza de los Reyes, Mexico City 11000, Mexico. floresh8@yahoo.com
Díaz-Cervantes
Paola
P
De la Mora
Gustavo
G
Zaga-Clavellina
Verónica
V
Uribe-Salas
Felipe
F
Castro
Ivone
I
D020101:Acrosome Reaction; D000818:Animals; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology*; D005260:Female; D005306:Fertilization / Q000187:drug effects* / Q000502:physiology; D005307:Fertilization in Vitro; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009640:Norethindrone / Q000031:analogs & derivatives / Q000494:pharmacology*; D009865:Oocytes / Q000378:metabolism*; D011897:Random Allocation; D011980:Receptors, Progesterone / Q000187:drug effects* / Q000378:metabolism
D003280:Contraceptives, Oral, Synthetic; D011980:Receptors, Progesterone; D009640:Norethindrone