Purified methoxychlor stimulates the reproductive tract in immature female mice

Methoxychlor is an estrogenic pesticide currently used as a substitute for DDT. The estrogenic effects of 98% pure methoxychlor or base-washed pure methoxychlor were examined on reproductive organs of immature mice and compared to control and estradiol-treated mice. Within 24 hours of birth, neonatal mice received 14 daily intraperitoneal injections of one of the following chemicals: sesame oil only, 10.0 micrograms of 17-beta estradiol, or 0.05 mg, 0.5 mg, or 1.0 mg of 98% pure methoxychlor, or 1.0 mg base-washed 98% pure methoxychlor. Equal doses (1.0 mg) of 98% pure or base-washed methoxychlor stimulated the reproductive organs of immature females such that the effects closely resembled those seen after estradiol treatments. In comparison to control mice, these pesticide treatments also induced precocious vaginal opening, persistent vaginal cornification, increased reproductive tract weights, and epithelial hypertrophy in both the vagina and uterus. However, only estradiol treatments significantly elevated albumin levels in the uterine fluid of the immature mice while the highest methoxychlor doses significantly increased the uterine cell heights when compared to all other groups.