Effects of methoxychlor treatment of pregnant mice on female offspring of the treated and subsequent pregnancies.
Reprod Toxicol 1992 Sep; 6(5):431-437
The effects of prenatal exposure to the chlorinated hydrocarbon pesticide methoxychlor (72435) on the developing ovary, and the effects on subsequent offspring of a mother exposed to methoxychlor during a previous pregnancy were investigated in mice. CD-1-mice were exposed by gavage to 0.025 milligrams (mg) estradiol-17beta, or 2.5, 5.0 or 7.5mg technical methoxychlor in sesame-oil daily from day six to day 15 of pregnancy. Offspring were evaluated for external malformations, and females were cross fostered to a mother exposed to the same or a different treatment group. Female offspring were killed at 8 to 10 weeks of age, and ovaries were evaluated histologically. Mothers were mated again and delivered a second litter, which was also evaluated. Pregnant females in the 7.5mg methoxychlor group displayed vaginal bleeding after two to three doses, and all fetuses were found to be dead. The length of gestation was significantly increased in mice exposed to estradiol- 17beta or 5.0mg methoxychlor. No differences were seen in the sex ratio of the exposure groups. External malformations were not seen. Females exposed prenatally to 5.0mg methoxychlor showed a larger percentage of atretic follicles. Offspring from the second litter of methoxychlor exposed mothers showed a significantly advanced time of vaginal opening.
NIOSH-Publication; NIOSH-Grant; Reproductive-system-disorders; Laboratory-animals; Reproductive-hazards; Prenatal-exposure; Chlorinated-hydrocarbon-pesticides
Anatomy Louisiana State University 1542 Tulane Avenue New Orleans, LA 70112
Louisiana State University, School of Medicine, Department of Anatomy, New Orleans, Louisiana