Prenatal phthalate exposure damages reproductive tissue in female mice

Phthalates are a ubiquitous family of chemicals that are used daily. In a new study, researchers investigated how these compounds affect tissue development in the reproductive systems of the offspring of female mice.

“Phthalates are found everywhere: construction products, personal care products, food and beverage containers and medical equipment,” said Jodi Flaws (EIRH / MME co-lead), professor of comparative biosciences at the University. of the Illinois Carl R. Woese Institute for Genomic Biology. “My research group is focused on how exposure to these environmental chemicals during pregnancy affects the offspring.”

Previous studies by the group have shown that phthalate mixtures disrupt female reproduction, alter organ weights and cause ovarian cysts. In the present study, they examine how these mixtures affect ovarian steroidogenesis – a process that produces hormones necessary for reproduction – in the offspring of female mice. The researchers also looked at folliculogenesis, which is essential for fertility. Follicles are small, fluid-filled sacs inside the ovaries that contain the eggs. They undergo maturation before releasing the egg during ovulation.

In the study, pregnant mice were orally administered either a control or a mixture of phthalates daily from the first day of gestation until birth. “The offspring’s reproductive system develops during this window. Mice are no longer exposed to any phthalates after they are born,” said Flaws.

The ovaries of the female offspring were then removed 60 days after birth and the tissues and their hormone levels were analyzed. “We looked at hormones such as estrogen, testosterone, and progesterone because they are important for normal fertility and tissue maintenance,” Flaws said.

Female mice whose mothers had been exposed to phthalates had lower levels of all three hormones compared to controls. “Since hormones are also important for other things in the body, such as cardiovascular health, bone health, and brain development, it is possible that there are other effects of the mixture,” Flaws said.

“The main take-home message is that if mothers are exposed to phthalates during pregnancy, it can interfere with the ability of female offspring to produce normal levels of hormones,” Flaws said. “We have seen that the mixture can inhibit the expression of important genes involved in the manufacture of hormones.

The researchers are now collaborating with other HRIA researchers to see if male offspring is similarly affected and to see if phthalate exposure affects other female reproductive organs. They will also investigate whether these changes are passed on to subsequent generations. “We need to better understand the mechanism behind these changes,” Flaws said. “We want to determine if these chemicals can increase tissue inflammation or if they can affect other parts of the body such as the uterus, hypothalamus, and pituitary gland.”

Flaws thanks all the undergraduate researchers who performed the experiments: Sarah Gill, Kathleen Leon and Justin Chiu. Other authors include Emily Brehm, a former graduate student, and Daryl Meling, a former postdoctoral fellow.