Time- and dose-dependent effects of ethanol on mouse embryonic stem cells.

Ethanol is a common solvent used with mouse embryonic stem (mES) cells in protocols to test chemicals for evidence of developmental toxicity. In this study, dose-response relationships for ethanol toxicity in mES cells were examined. For cells maintained in an undifferentiated state, ethanol significantly reduced viable cell numbers with estimated half maximal inhibitory concentrations of 1.

Endosulfan induces CYP2B6 and CYP3A4 by activating the pregnane X receptor.

Endosulfan is an organochlorine pesticide commonly used in agriculture. Endosulfan has affects on vertebrate xenobiotic metabolism pathways that may be mediated, in part, by its ability to activate the pregnane X receptor (PXR) and/or the constitutive androstane receptor (CAR) which can elevate expression of cytochrome P450 (CYP) enzymes. This study examined the dose-dependency and receptor specificity of CYP induction in vitro and in vivo.

Effects of paraquat on development of preimplantation embryos in vivo and in vitro.

Paraquat can cause oxidative stress through redox cycling, and preimplantation embryos are sensitive to oxidative stress in vitro. In this study, the effects of paraquat on preimplantation embryo development were examined. Exposure of preimplantation embryos (collected on the day after ovulation) to paraquat in vitro for 24 h at concentrations as low as 8 microM caused a significant decrease in the percentage of 8-cell embryos and an increase in the percentage of compacted morulae, but the content of reduced glutathione (GSH) in embryos was not changed.

Role of glutathione in reproductive tract secretions on mouse preimplantation embryo development.

We investigated the hypothesis that glutathione (GSH) in reproductive tract secretions (RTS) protects the preimplantation embryo from endogenous reactive oxygen species and is important for normal development during the embryo's sensitive period when it is incapable of synthesizing GSH de novo. Mice were administered buthionine sulfoximine (BSO) to inhibit GSH synthesis and decrease GSH concentration in RTS. Embryos were then allowed to develop either in vivo or in vitro in the presence of RTS and the GSH concentration of the embryos was quantified by HPLC and embryonic development was recorded.