Featured Research

from universities, journals, and other organizations

Exposure to environmental chemicals in the womb reprograms the rodent brain to disrupt reproduction

Date:
June 26, 2012
Source:
Endocrine Society
Summary:
Prenatal exposure to the environmental contaminants polychlorinated biphenyls, or PCBs, causes long-term changes to the developing brain that have adverse effects on reproductive function later in life, a new study finds.

Prenatal exposure to the environmental contaminants polychlorinated biphenyls, or PCBs, causes long-term changes to the developing brain that have adverse effects on reproductive function later in life, a new study finds.

Results will be presented Saturday at The Endocrine Society's 94th Annual Meeting in Houston.

The study used rats, whose genes and molecules in the hypothalamus -- the region of the brain important for reproductive function -- are virtually identical to those in humans, according to co-author Andrea Gore, PhD, professor of pharmacology and toxicology at the University of Texas at Austin. These PCB-induced brain changes delayed puberty in male offspring and disrupted reproductive cycles in adult female offspring, she reported.

In addition, the researchers identified five genes that PCB disrupted. Gore said that all five are critical to the normal hypothalamic control of reproduction.

"By identifying five genes that are most perturbed by PCBs in the developing rat brain, we may one day be able to develop targeted interventions or therapeutics for reproductive problems, focusing on these molecular endpoints," Gore said.

PCBs are industrial chemicals used in many plastics, insulation materials, floor finishes and electrical equipment before their ban in 1979, according to the U.S. Environmental Protection Agency. Still present in air, water and soil, PCBs are known endocrine disruptors, compounds in the environment that interfere with hormones and their actions in the body.

In this study, funded by the National Institutes of Health, the investigators exposed rats late in pregnancy to low levels of a mixture of PCBs, as one might encounter in the environment, Gore said. Control rats received an inactive substance. After birth, the offspring had monitoring throughout their life to determine if their reproductive development was disrupted. The research team also examined the brains of some of the animals at different ages to determine whether and how prenatal exposure affected gene expression in the hypothalamus.

Effects on gene expression depended on age, the scientists found. Effects were most profound on day 15 in the life of males and day 45 in females, corresponding roughly to childhood and after puberty, respectively.

In females, PCB exposure also resulted in altered reproductive cycles in adulthood, and in males, puberty was delayed, compared with the offspring of nonexposed control rats.

Depending on age and sex, five genes in the hypothalamus were affected by PCB treatment: Kiss1 (which stands for kisspeptin 1), Kiss1r (kisspeptin 1 receptor), Gper (G-protein-coupled estrogen receptor), Tac2 (neurokinin B) and Pdyn (prodynorphin). These genes are known to be very important for the control of reproduction. However, because the effects of PCBs on the brain were specific to age, sex and developmental stage, Gore suggested that PCBs might alter development of the hypothalamus, rather than just altering individual genes.

"We can look gene by gene, but it's the big picture of how these genes are affected in concert that's important to development," she said.


Story Source:

The above story is based on materials provided by Endocrine Society. Note: Materials may be edited for content and length.


Cite This Page:

Endocrine Society. "Exposure to environmental chemicals in the womb reprograms the rodent brain to disrupt reproduction." ScienceDaily. ScienceDaily, 26 June 2012. <www.sciencedaily.com/releases/2012/06/120626113917.htm>.
Endocrine Society. (2012, June 26). Exposure to environmental chemicals in the womb reprograms the rodent brain to disrupt reproduction. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2012/06/120626113917.htm
Endocrine Society. "Exposure to environmental chemicals in the womb reprograms the rodent brain to disrupt reproduction." ScienceDaily. www.sciencedaily.com/releases/2012/06/120626113917.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins