Developmental and lactational exposure to environmentally relevant concentrations of dieldrin does not alter pregnancy outcome and mammary gland morphology in BALB/c mice.
The objectives of this study were to: (1) determine the dosing range necessary to produce serum levels of dieldrin in mice representative of human body burdens; and (2) define the effect of developmental exposure to environmentally relevant concentrations of dieldrin on mammary gland development. Sexually mature female BALB/c mice (n=140) were randomly assigned to receive vehicle, 0.45, 2.25, 4.5, and 22.5 microg dieldrin/g body weight (BW)/day. Serum levels of dieldrin were quantified by gas chromatography in pooled samples (n=4/treatment group). Target levels of 10-30 ng/ml were achieved in 0.45 and 2.25 microg/g dose groups by the end of 2 weeks of treatment. Vehicle or dieldrin (0.45, 2.25, and 4.5 microg/g BW) was administered weekly to sexually mature female BALB/c mice (n=48) throughout mating, pregnancy, and lactation. Treatments had no effect on fertility parameters in dams or mammary gland morphology at sexual maturity. Developmental exposure to dieldrin has no effect on mammary gland development in aged BALB/c mice.
Reproductive Biology Division, Department of Obstetrics and Gynecology, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, Canada. fosterw@mcmaster.ca
Warren G
WG
Foster
Pezhman
P
Mirshokraei
Alison C
AC
Holloway
Bingjun
B
Zhang
D000818:Animals; D002849:Chromatography, Gas; D004026:Dieldrin / Q000097:blood / Q000633:toxicity*; D004781:Environmental Exposure; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000033:anatomy & histology*; D018811:Maternal Exposure; D051379:Mice; D008807:Mice, Inbred BALB C; D010575:Pesticides / Q000097:blood / Q000633:toxicity*; D011247:Pregnancy; D011256:Pregnancy Outcome
D010575:Pesticides; D004026:Dieldrin