Hypotaurine in spermatozoa and genital secretions and its production by oviduct epithelial cells in vitro.

Taurine and/or hypotaurine are necessary compounds for sperm capacitation, fertilization and embryo development. Hypotaurine has a protective role against peroxidative damage. The object of this work was, on the one hand, to determine the precise amounts of hypotaurine and taurine in the sperm environment at the moment of fertilization, and on the other hand to evaluate the production of hypotaurine and taurine by oviduct epithelial cells. Hypotaurine and taurine were quantified in spermatozoa and seminal and tubal fluid of various species, and in secretions by oviduct epithelial cell layers in vitro. Significant amounts of taurine and hypotaurine were identified. Both compounds were quantified in pre-ovulatory follicular fluid, i.e. in one of the fluids present at the site of fertilization. We also observed that hypotaurine and taurine are synthesized and secreted in vitro by oviduct epithelial cells. We were able to demonstrate that hypotaurine is stable when added to an in-vitro fertilization (IVF) culture medium. The effects of this compound should be more carefully studied in human IVF.