The reversible reproductive toxicity of 5-fluorouracil in mice.

5-Fluorouracil (5-FU) is a "cytotoxic" drug used for cancer chemotherapy, which inhibits cells division via affecting DNA synthesis. Although being widely used for cancer treatment, 5-FU has non-negligible side effects. In the present study, the effects of 5-FU on oocyte and early embryonic development were investigated. Multiple intraperitoneal administration of 5-FU (50 mg/kg/day) in female mice resulted in small ovarian size and reduced number of corpus luteum in the ovary, and lead to ovulation failure. However, these defects could be recovered after one week. In vitro experiments further indicated that exposure to 5-FU inhibited oocytes maturation and reduced developmental potential of pre-implantation embryos. Our data suggested that 5-FU has negative impact on ovarian function, oocyte and early embryonic development, but the adverse effect could be reversed after withdrawal of 5-FU administration.