Fluoxetine Treatment during In Vitro Fertilization and Culture Increases Bovine Embryonic Development

Abstract

K+ channels are involved in the regulation of a variety of physiological functions, including proliferation, apoptosisand differentiation, in mammalian cells. Our previous study demonstrated that the blockage of K+ channels inhibitsmouse early embryonic development. This study was designed to identify the effect of K+ channels during bovineembryonic development. K+ channel blockers (tetraethylammonium (TEA), BaCl2, quinine, ruthenium red andfluoxetine) were added to the culture medium during in vitro fertilization (IVF) for 6 h to first identify the short-termeffect of these chemicals. Among K+ channel blockers, fluoxetine, which is used as a selective serotonin reuptakeinhibitor, significantly increased the blastocyst formation rate by approximately 6% when compared to control. Duringthe in vitro maturation (IVM) of immature oocytes and the in vitro culture (IVC) of embryos, the oocytes and embryoswere exposed to fluoxetine for either a short-term (6 h) or a long-term (24 h) to compare the embryonic developmentin response to exposure time. The 6 h exposure to fluoxetine during IVM did not affect the blastocyst formation rate,but the rate of blastocyst formation was reduced after the 24 h exposure. On the other hand, embryonic developmentincreased approximately 10% in both groups of embryos exposed to fluoxetine for 6 and 24 h during IVC. Takentogether, fluoxetine treatment during IVF and IVC, but not IVM, enhances bovine embryonic development. Theseresults suggest that fluoxetine-modulated signals in oocytes and embryos could be an important factor towardsenhancing bovine embryonic development.