The weeks shown in color represent the start and end points of chemical exposure for each study.

Study Results Study Details References

Results for Dioxin (TCDD)

Decreased P450scc mRNA at 1.0 μg/kg at 16 days of age; decreased p450arom and StAR mRNA levels at 0.2 μg/kg at 14 days of age; decreased aromatase enzyme activity in ovarian follicles at 1.0 μg/kg at 14 days of age

Subjects: Sprague-Dawley rats

Chemical: Dioxin (TCDD)

Low doses tested: 0.04, 0.2 or 1.0 μg/kg bw

Route of administration: dissolved in corn oil, sonicated, and delivered via gavage

Exposure duration: gestational day 13 – single dose (comparable to human prenatal development from approximately day 1 of week 5 to day 1 of week 6)

Age of measurement: 10 through 16 days of age

Reference [PubMed Link]
Myllymaki SA, Haavisto TE, Brokken LJS, Viluksela M, Toppari J, Paranko J. 2005. In utero and lactational exposure to TCDD; Steroidogenic outcomes differ in male and female rat pups. Toxicol Sci 88(2):534-544.
Study Results Study Details References

Results for Dioxin (TCDD)

Increased fat pad length for DBA/2J mice fed high fat diet (HFD)

Subjects: C57BL/6J and DBA/2J mice

Chemical: Dioxin (TCDD)

Low doses tested: 1.0 μg/kg bw

Route of administration: dissolved in olive oil and delivered by gavage

Exposure duration: gestation day 12.5 – single dose (comparable to human prenatal development from approximately day 1 of week 5 to day 1 of week 6)

Age of measurement: birth through 35 days of age

Reference [PubMed Link]
La Merrill M, Kuruvilla BS, Pomp D, Birnbaum LS, Threadgill DW. 2009. Dietary fat alters body composition, mammary development, and cytochrome p450 induction after maternal TCDD exposure in DBA/2J mice with low-responsive aryl hydrocarbon receptors. Environ Health Perspect 117(9):1414-1419.
Study Results Study Details References

Results for Dioxin (TCDD)

Decreased branch elongation, number and size of terminal buds for DBA/2J mice fed HFD, decreased size of terminal end buds for DBA/2J mice fed low fat diet

Subjects: C57BL/6J and DBA/2J mice

Chemical: Dioxin (TCDD)

Low doses tested: 1.0 μg/kg bw

Route of administration: dissolved in olive oil and delivered by gavage

Exposure duration: gestation day 12.5 – single dose (comparable to human prenatal development from approximately day 1 of week 5 to day 1 of week 6)

Age of measurement: birth through 35 days of age

Reference [PubMed Link]
La Merrill M, Kuruvilla BS, Pomp D, Birnbaum LS, Threadgill DW. 2009. Dietary fat alters body composition, mammary development, and cytochrome p450 induction after maternal TCDD exposure in DBA/2J mice with low-responsive aryl hydrocarbon receptors. Environ Health Perspect 117(9):1414-1419.
Study Results Study Details References

Results for Dioxin (TCDD)

Increased mammary lesions in DMBA-treated mice fed high-fat diet; increased terminal end buds in mice fed low-fat diet; decreased terminal end buds in mice fed high-fat diet; increased epithelial Cyp1b1 mRNA expression and decreased Comt mRNA expression in mice fed high-fat diet; increased Cyp1b1 mRNA expression in tumors of DMBA-treated mice.

Subjects: FVB/NJ mice

Chemical: Dioxin (TCDD)

Low doses tested: 1.0 μg/kg bw

Route of administration: dissolved in olive oil and delivered by gavage

Exposure duration: gestation day 12.5 – single dose (comparable to human prenatal development from approximately day 1 of week 5 to day 1 of week 6)

Age of measurement: birth through adulthood

Reference [PubMed Link]
La Merrill M, Harper R, Birnbaum LS, Cardiff RD, Threadgill DW. 2010 May. Maternal dioxin exposure combined with a diet high in fat increases mammary cancer incidence in mice. Environ Health Perspect 118(5):596-601.