Effects of neonatal administration of zearalenone on the reproductive physiology of female mice.

The effects of neonatal (1-10 days) administration of various doses (5-30 micrograms/animal) of zearalenone, a mycotoxin, on the sexual maturation and reproductive physiology of female ICR mice were investigated. The drug was found to have mimic estrogen actions, causing delayed vaginal opening, persistent estrus (60-80% incidence) and sterility. Daily doses of zearalenone (10-30 micrograms/animal) for 3-5 neonatal days resulted in infertility accompanied by thickening of the vaginal epithelium, even after ovariectomy and adrenalectomy, indicating mucosal independence of endogenous estrogen. Thus, it may be possible that zearalenone acts by binding irreversibly to estrogen receptors in the target tissues.