Influence of thyroid hormone on mouse preantral follicle development in vitro.
OBJECTIVE
To evaluate the role of 3,3',5-triiodothyronine (T(3)) on ovarian follicle development in vitro.


METHODS
Experimental study.


METHODS
University reproductive biology unit.


METHODS
CD1 mice (female).


METHODS
In vitro culture.


METHODS
Assessment of follicle and oocyte development following a 6-day culture with FSH (100 mU/mL), (Bu)(2)cAMP (0.5 mM), and T(3) (1-100 nM), alone or in combination.


RESULTS
A high percentage of in vitro grown (IVG) FSH-stimulated follicles formed an antral cavity (AC), while the addition of T(3) (100 nM) significantly reduced this response in a statistically significant manner. A statistically significant recovery of AC formation was obtained by limiting exposure to 4 days of culture. Formation of AC was induced by (Bu)(2)cAMP, which prevented T(3)-mediated suppression of AC formation. Under different conditions, high proportions of germinal vesicle-arrested IVG oocytes displayed condensed chromatin configuration. The capacity to undergo germinal vesicle breakdown (GVBD) was similar in all groups, and a statistically significant reduction in the percentage of oocytes with PB1 was recorded when T(3) was added to FSH or (Bu)(2)cAMP. This ability was partially recovered by removing T(3) on day 4 of culture.


CONCLUSIONS
Exposure to high T(3) concentrations can impair preantral follicle development, but this effect can be partly reverted by restoring a physiological hormonal milieu before follicle commitment to antral development.
Cecconi
Sandra
S
Dipartimento di Scienze e Tecnologie Biomediche-L'Aquila, Via Vetoio 10, 67100 L'Aquila, Italy. cecconi@univaq.it
Rossi
Gianna
G
Coticchio
Giovanni
G
Macchiarelli
Guido
G
Borini
Andrea
A
Canipari
Rita
R
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002417:Cattle / Q000097:blood / Q000196:embryology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002843:Chromatin / Q000187:drug effects / Q000648:ultrastructure; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005312:Fetal Blood; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000166:cytology; D006080:Ovarian Follicle / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D014284:Triiodothyronine / Q000494:pharmacology*
D002843:Chromatin; D014284:Triiodothyronine; D004958:Estradiol; D003994:Bucladesine; D005640:Follicle Stimulating Hormone