Role of hydrogen sulfide in the female reproductive tract

It is well established that hydrogen sulfide (H ₂S) has a signaling role in the body. So far it has been shown that H ₂S is produced by intra-uterine tissues in the pregnant rat and the human placenta. Two main enzymes responsible for H ₂S production, cystathionine- synthase and cystathionine-lyase, have been demonstrated in the pregnant and nonpregnant uterus, fetal membranes and placenta in the rat, and in human placenta. H ₂S donors have been shown to inhibit contraction of the pregnant rat uterus. H ₂S could play a role in maintaining uterine quiescence during pregnancy, as an oxygen sensor and vasodilator in the placenta, or as an anti-inflammatory. More research is required in this area to elucidate the roles of H ₂S in the female reproductive tract and its mechanisms of action.