Exposure to bisphenol A in young adult mice does not alter ovulation but does alter the fertilization ability of oocytes.
Follicle growth culminates in ovulation, which allows for the expulsion of fertilizable oocytes and the formation of corpora lutea. Bisphenol A (BPA) is present in many consumer products, and it has been suggested that BPA impairs ovulation; however, the underlying mechanisms are unknown. Therefore, this study first evaluated whether BPA alters ovulation by affecting folliculogenesis, the number of corpora lutea or eggs shed to the oviduct, ovarian gonadotropin responsiveness, hormone levels, and estrous cyclicity. Because it has been suggested (but not directly confirmed) that BPA exerts toxic effects on the fertilization ability of oocytes, a second aim was to evaluate whether BPA impacts the oocyte fertilization rate using an in vitro fertilization assay and mating. The possible effects on early zygote development were also examined. Young adult female C57BL/6J mice (39 days old) were orally dosed with corn oil (vehicle) or 50 μg/kgbw/day BPA for a period encompassing the first three reproductive cycles (12-15 days). BPA exposure did not alter any parameters related to ovulation. Moreover, BPA exposure reduced the percentage of fertilized oocytes after either in vitro fertilization or mating, but it did not alter the zygotic stages. The data indicate that exposure to the reference dose of BPA does not impact ovulation but that it does influence the oocyte quality in terms of its fertilization ability.
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Teresita Rocio
TR
Moore-Ambriz
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Deyanira Guadalupe
DG
Acuña-Hernández
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Brenda
B
Ramos-Robles
Área Académica de Medicina, Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Hidalgo 42000, México.
Manuel
M
Sánchez-Gutiérrez
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Ramsés
R
Santacruz-Márquez
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Adolfo
A
Sierra-Santoyo
Instituto Politécnico Nacional-UPIBI, México D.F. 07738, México.
Belem
B
Piña-Guzmán
Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México.
Mineko
M
Shibayama
Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D.F. 07360, México. Electronic address: mihernandez@cinvestav.mx.
Isabel
I
Hernández-Ochoa
D000818:Animals; D001559:Benzhydryl Compounds / Q000009:adverse effects*; D030762:Estrous Cycle / Q000187:drug effects; D005260:Female; D005306:Fertilization / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000187:drug effects*; D006080:Ovarian Follicle / Q000187:drug effects; D010060:Ovulation / Q000187:drug effects*; D010636:Phenols / Q000009:adverse effects*; D015053:Zygote / Q000187:drug effects; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds
Bisphenol A; In vitro fertilization; In vivo fertilization; Oocyte; Ovulation