Endocrine Disruptors

Bisphenol A alters the development of the rhesus monkey mammary gland

PNAS-Proceedings of the National Academy of Sciences of the United States of America

Bisphenol A alters the development of the rhesus monkey mammary gland

Andrew P. Tharpa,1,Maricel V. Maffinia,1,Patricia A. Huntb,Catherine A. VandeVoortc,Carlos Sonnenscheina, and Ana M. Sotoa,2

Edited* by Joan V. Ruderman, Harvard Medical School, Boston, MA, and approved April 2, 2012 (received for review January 3, 2012)

Abstract

The xenoestrogen bisphenol A (BPA) used in the manufacturing of various plastics and resins for food packaging and consumer products has been shown to produce numerous endocrine and developmental effects in rodents. Exposure to low doses of BPA during fetal mammary gland development resulted in significant alterations in the gland’s morphology that varied from subtle ones observed during the exposure period to precancerous and cancerous lesions manifested in adulthood. This study assessed the effects of BPA on fetal mammary gland development in nonhuman primates. Pregnant rhesus monkeys were fed 400 μg of BPA per kg of body weight daily from gestational day 100 to term, which resulted in 0.68 ± 0.312 ng of unconjugated BPA per mL of maternal serum, a level comparable to that found in humans. At birth, the mammary glands of female offspring were removed for morphological analysis. Morphological parameters similar to those shown to be affected in rodents exposed prenatally to BPA were measured in whole-mounted glands; estrogen receptor (ER) α and β expression were assessed in paraffin sections. Student's t tests for equality of means were used to assess differences between exposed and unexposed groups. The density of mammary buds was significantly increased in BPA-exposed monkeys, and the overall development of their mammary gland was more advanced compared with unexposed monkeys. No significant differences were observed in ER expression. Altogether, gestational exposure to the estrogen-mimic BPA altered the developing mammary glands of female nonhuman primates in a comparable manner to that observed in rodents.

http://www.pnas.org/content/early/2012/05/01/1120488109.short 5/9/2012

What are Endocrine Disruptors?

hormonepic

Your endocrine system is essential to our health! This system regulates hormones with in the body that influence every cell, tissue, organ and function in our bodies. The endocrine system regulates mood, growth and development, tissue function, metabolism, as well as sexual function and reproductive processes.

An endocrine disruptor is a chemical that alters normal function of this system. A variety of chemicals have been found to disrupt the endocrine system; some mimic hormones produced by the endocrine system others can block these hormones from doing their job.

It is important as a community to increase our awareness of: Where we are coming into contact with endocrine disruptors? How we will address these exposures? And the personal actions we take to protect future generations.

Can Endocrine Disruptors Contribute to the Feminizing of Boys?

1/11/2012 eMaxHealth

Environmental Contaminants Contribute to Male Infertility

Polychlorinated Biphenyls (PCBs) are no longer commercially produced in the United States, but continue to wreak havoc on our health today. New research published in the journal Environmental Health Perspectives has linked PCBs and other environmental chemicals to sperm abnormalities and male infertility. Previous studies have found that infertility affects 15% of couples, but that about 50% of male infertility is potentially correctable. Infertility is defined as the inability to conceive after one year of unprotected intercourse. Melissa Perry ScD MHS, professor and chair of the Department of Environmental and Occupational Health at the George Washington School of Public Health and Health Services, led an observational study on environmental exposure to organochlorine chemicals. The research team studied 192 men who were part of couples that were “sub-fertile” – meaning that they had a lower ability to become pregnant than normal, healthy couples. Blood was sampled for the presence of chemicals such as PCBs and p,p’-DDE, the main metabolite of the insecticide DDT. Semen samples were taken and assessed for sperm disomy, which occurs when sperm cells have an abnormal number of chromosomes. All men have a certain number of sperm with such abnormalities, but those with higher levels of PCBs and DDE had significantly higher rates. Polychlorinated Biphenyl was previously used in products and materials such as transformers, capacitors, and other electrical equipment such as voltage regulators and electromagnets. Other products containing PCBs including cable insulation, adhesives and tapes, oil-based paint, caulking, plastics, carbonless copy paper and floor finish. The EPA banned its use in 1979. Today, PCBs can still be released into the environment from poorly maintained hazardous waste sites that contain PCBs, illegal or improper dumping of PCB wastes, leaks or releases from electrical transformers and disposal of PCB-containing consumer products into landfills not designed to handle hazardous waste. DDE (1,1-DICHLORO-2,2-BIS(p-CHLOROPHENYL) ETHYLENE) is a breakdown product of DDT which was banned in the United States in 1972, except in the case of a public emergency. The EPA has classified DDE as a Group B2 probable human carcinogen. Previous animal studies have found that DDE has adverse effects on spermatogenesis and decreased testicular weights. Human exposure to DDE appears to be primarily through food; levels in the air and water samples are low according to a report from the US Department of Health and Human Services.

“This research adds to the already existing body of evidence suggesting that environmental exposure to certain chemicals can affect male fertility and reproduction. We need to further understand the mechanisms through which these chemicals impact sperm,” said Dr. Perry. “While we cannot avoid chemi

Highly Exposed to Phthalates as Fetuses, Female Mice Have Altered Reproductive Lives

A striking degree of abnormal cell growth Mammary tissue of control mice (left) and mice exposed as fetuses to

A striking degree of abnormal cell growth Mammary tissue of control mice (left) and mice exposed as fetuses to 1,000 mg per kg of mother’s body weight of MEHP, a common ingredient in plastics. (Black bar is 1 mm.) (Credit: Hixon Lab/Brown University)

1,000 mg per kg of mother’s body weight of MEHP, a common ingredient in plastics. (Black bar is 1 mm.) (Credit: Hixon Lab/Brown University)ScienceDaily (Mar. 16, 2012) — Many environmental and public health officials are concerned about the potential health effects of phthalates, which are common chemicals used to make plastics softer and more pliable. In the first study to examine what effect in utero doses of phthalates have on the reproductive system of mice, Brown University toxicologists found that extremely high doses were associated with significant changes, such as a shortened reproductive lifespan and abnormal cell growth in mammary glands.

Female mouse fetuses exposed to very high doses of a common industrial chemical that makes plastics more pliable develop significant reproductive alterations and precancerous lesions as they grow up, according to a new toxicology study conducted at Brown University.

The administered doses of MEHP, the chemical that results when animals metabolize the industrial phthalate DEHP, were much higher than any normal environmental exposure that people or animals would encounter, said Mary Hixon, assistant professor of pathology and laboratory medicine (research) in The Warren Alpert Medical School of Brown University and a study co-author.

"For these doses, you'd have to be eating the plastic or drinking the plastic," she said. "The real risk is probably minimal for most people."

But when toxicologists set out to determine the effect of a chemical on an organism, they often start with atypically high doses and work their way down to the levels where any adverse effects disappear. Until now, no one had done such a study on the effects of exposure to doses of MEHP in adult mice while they were still in utero.

Research and Real World

Pubertal assessment method and baseline characteristics in a mixed longitudinal study of girls

Biro FM, Galvez MP, Greenspan LC, Succop PA, Vangeepuram N, Pinney SM, Teitelbaum S, Windham GC, Kushi LH, Wolff MS.

Source-Cincinnati Children's Hospital Medical Center, Adolescent Medicine (ML 4000), and Department of Environmental Health, University of Cincinnati College of Medicine, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA. This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Abstract

OBJECTIVES:

The objective of this study was to describe the assessment methods and maturation status for a multisite cohort of girls at baseline recruitment and at ages 7 and 8 years.

preventionisthecure.org

Bisphenol A alters the development of the rhesus monkey mammary gland

What are Endocrine Disruptors?

Can Endocrine Disruptors Contribute to the Feminizing of Boys?

Highly Exposed to Phthalates as Fetuses, Female Mice Have Altered Reproductive Lives

Research and Real World