title: Contribution of culture media to oxidative stress and its effect on human oocytes.
abstract: The adverse effects of reactive oxygen species (ROS) on many aspects of reproduction are well documented. However, much less is known regarding the contribution of culture media to the oxidative stress of gametes during assisted reproductive techniques. This study measured the generation of ROS by culture media during IVF procedures and its effects on human oocytes. Commercially supplied culture media generated ROS at various rates, depending on the composition, whereas follicular fluid generated ROS at a much lower level. The incubation of cumulus-oocyte complexes (COC) in culture media induced marked lipid peroxidation compared with levels found in freshly retrieved COC. This plasma membrane damage, measured with the quenching of cis-parinaric acid fluorescence assay, was attenuated by supplementation of the medium with alpha-tocopherol or catalase. Moreover, there was an association between ROS production by culture medium and thiolic content consumption within the oocytes, suggesting that the intracellular reduced glutathione pool was partially depleted during in-vitro manipulation. The results show that culture medium could damage oocytes (and consequently embryo development) depending on their composition, and it is proposed that current IVF protocols could be revised in order to decrease ROS generation.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Extremadura, Badajoz-06071, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Martín-Romero
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Miguel-Lasobras
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Domínguez-Arroyo
authors.forename: Ernesto
authors.initials: E
authors.lastname: González-Carrera
authors.forename: Ignacio Santiago
authors.initials: IS
authors.lastname: Alvarez
mesh_terms: D000328:Adult; D003470:Culture Media / Q000009:adverse effects* / Q000737:chemistry; D054885:Cumulus Cells / Q000378:metabolism; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D015227:Lipid Peroxidation; D009865:Oocytes / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*
chemical_list: D003470:Culture Media; D017382:Reactive Oxygen Species; D005978:Glutathione