title: The thiol reagent, thimerosal induces intracellular calcium oscillations in mature human oocytes.
abstract: The aim of this study was to investigate the effects of thimerosal on intracellular calcium in human oocytes related to the stage of nuclear maturity. A total of 20 oocytes from superovulated women undergoing gamete intra-Fallopian transfer (GIFT) were studied. The calcium-sensitive fluorescent dye Fura-2 was used to monitor intracellular calcium. Regular oscillations in the concentration of cytosolic calcium were observed in 13 out of 20 oocytes following exposure to thimerosal; five oocytes did not respond to thimerosal treatment, and spontaneous oscillations of cytosolic free calcium were recorded in two oocytes. Thimerosal induced oscillations of intracellular calcium in a significantly higher proportion of metaphase II oocytes (10/11) compared with metaphase I oocytes (3/8; P < 0.2). These findings demonstrate that thimerosal is a potentially useful agent for the study of the calcium signalling processes in human eggs and suggest that the underlying cellular mechanisms develop at a relatively late stage of oocyte maturation.
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK.
authors.forename: M
authors.initials: M
authors.lastname: Herbert
authors.forename: A P
authors.initials: AP
authors.lastname: Murdoch
authors.forename: J I
authors.initials: JI
authors.lastname: Gillespie
mesh_terms: D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects*; D016922:Cellular Senescence; D005260:Female; D015181:Gamete Intrafallopian Transfer; D006801:Humans; D008540:Meiosis / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D013849:Thimerosal / Q000494:pharmacology*
chemical_list: D013439:Sulfhydryl Reagents; D013849:Thimerosal; D002118:Calcium