Navigation Links
Study finds reproductive health effects from low doses of bisphenol-A
Date:6/17/2009

New research from North Carolina State University and the National Institute of Environmental Health Sciences (NIEHS) shows significant reproductive health effects in rats that have been exposed to bisphenol-A (BPA) at levels equivalent to or below the dose that has been thought not to produce any adverse effects.

BPA is a chemical found in baby bottles, water bottles, canned foods and an array of other consumer products. The potential health effects of BPA are currently the subjects of intense debate.

The study found that female rats exposed to a BPA dose of 50 micrograms per kilogram of body weight (g /kg) in their first four days of life experienced early onset of puberty. Female rats exposed to 50 milligrams per kilogram of body weight (mg/kg) during their first four days of life developed significant ovarian malformations and premature loss of their estrus cycle.

"The 50 mg/kg level is important," says lead researcher Dr. Heather Patisaul, "because it is equivalent to the U.S. Environmental Protection Agency's 'Lowest Observable Adverse Effect Level' for BPA. So, by definition, we should not have seen significant effects at or below this level, but we did."

Patisaul, an assistant professor of biology at NC State, explains that the 50 g /kg level is also significant because it is EPA's listed reference dose for BPA meaning it is the level of BPA that EPA says a person can be exposed to on a daily basis without expecting any adverse effects after a lifetime of exposure.

Patisaul stresses that the research was done on rats, making it difficult to determine its applicability to humans, but notes that "this adds to a growing body of evidence that exposure to low doses of BPA during development can impact female reproductive health."

The female rats in the study were exposed during the first four days of life because that is a sensitive developmental window for the rats, similar to a sensitive developmental stage that takes place for humans when they are still in the womb.

While exposure to the lowest dose, 50 g /kg, resulted in early onset of puberty in the rats, exposure to higher dose had more complicated results.

When exposed to the higher 50 mg/kg dose, the female rats developed cyst-like formations in their ovaries. The ovaries also developed fewer so-called "corpora lutea" structures than normal. Corpora lutea appear after ovulation and are essential to fertility because they produce a hormone called progesterone. If an ovary does not produce enough progesterone, it is impossible for a female to sustain a pregnancy. The lack of corpora lutea likely indicate that the female rats were no longer ovulating and would probably be infertile.

Exposure to the higher 50 mg/kg dose also resulted in the female rats prematurely losing their estrous cycle. The researchers determined this by observing a lack of change in the skin cells of the female reproductive tract of the rats across the estrous cycle. These cellular changes indicate a normal estrus cycle.


'/>"/>

Contact: Matt Shipman
matt_shipman@ncsu.edu
919-515-6386
North Carolina State University
Source:Eurekalert

Related medicine news :

1. Penn study finds pro-death proteins required to regulate healthy immune function
2. New study shows promise in reducing surgical risks associated with surgical bleeding
3. Study, meta-analysis examine factors associated with death from heatstroke
4. Study suggests loss of 2 types of neurons -- not just 1 -- triggers Parkinsons symptoms
5. Study says COPD testing is not measuring up
6. Preclinical study suggests organ-transplant drug may aid in lupus fight
7. Ability to cope with stress can increase good cholesterol in older white men, study finds
8. High alcohol consumption increases stroke risk, Tulane study says
9. Mailman School of Public Health study examines link between racial discrimination and substance use
10. Pitt study finds inequality in tobacco advertising
11. Stanford study highlights cost-effective method of lowering heart disease risks
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/2/2016)... ... ... Lori G. Cohen and Sara K. Thompson , shareholders in global law ... 21st Drug & Medical Device Litigation Conference , taking place in New York Dec. ... chairs the firm’s Pharmaceutical, Medical Device & Health Care Litigation Practice and the Trial ...
(Date:12/2/2016)... ... , ... Advanced Inc., a leading provider of travel therapy and travel nursing ... as Advanced Inc.’s Chief Financial Officer, effective December 1, 2016. Jason previously served as ... operational leadership experience to Advanced Inc. He began his career in finance at Ernst ...
(Date:12/2/2016)... ... ... With the number of pain management programs available for people suffering with constant ... works for them. When an inventor from Suisun City, Calif., was unsuccessful in finding ... it with others. , He developed a prototype for PRO GO MASSAGE to relieve ...
(Date:12/2/2016)... ... December 02, 2016 , ... CloudLIMS.com, a ... SaaS LIMS, CloudLIMS Lite. CloudLIMS Lite helps biobanks, clinical, research and testing laboratories ... and disposal. The new version is a faster and a more efficient product, ...
(Date:12/2/2016)... ... 02, 2016 , ... Yisrayl Hawkins, at The House of Yahweh in Abilene, ... into Bible Prophecy. Yisrayl says this generation, known as the Last Generation, started in ... the details line up exactly with Bible Prophecy – a protected way for those ...
Breaking Medicine News(10 mins):
(Date:12/2/2016)... , December 2, 2016 On ... Committee honored excellence in research, development and innovation in ... gala dinner was held in the presence of Sergey ... Russian Federation , Natalia Sanina, First ... Mikhail Murashko , Head of Roszdravnadzor, National Service of ...
(Date:12/2/2016)... CVS Health Corporation (NYSE: CVS ... City on Thursday, December 15, 2016, beginning at 8:00 a.m. (ET). Senior ... an in-depth review of the company,s strategies to drive ... also discuss 2017 earnings guidance during the event. ... will be broadcast simultaneously on the Investor Relations portion ...
(Date:12/2/2016)... -- On Thursday, the NASDAQ Composite and the ... Dow Jones Industrial Average managed to stay in green. Losses ... prompted Stock-callers this morning to look at the performances of ... ), Smith & Nephew PLC (NYSE: SNN ), ... Therapeutics Inc. (NASDAQ: KOOL ). You can access ...
Breaking Medicine Technology: