Navigation Links
Birth control has long-term effect on hormone exposure
Date:10/20/2008

WINSTON-SALEM, N.C. Researchers at Wake Forest University School of Medicine may be one step closer to understanding why past oral contraceptive use dramatically lowers the risk of ovarian and uterine cancers later in life.

While studying the effect of post-menopausal dietary soy consumption on estrogen metabolism in cynomolgus monkeys, Latanya M. Scott, Ph.D., discovered that monkeys who had been given birth control earlier in life had a reduced amount of estrogen excreted in their urine. The research was done in collaboration with Xia Xu, Ph.D., and Timothy Veenstra, Ph.D. at Science Applications International Corporation-Frederick, Inc., in Frederick, Md., who have developed novel methods for analysis of urinary estrogens.

The discovery was particularly noteworthy because it was found three years after oral contraceptive treatment was stopped, roughly the equivalent of a decade of life in a human.

While researchers have known for many years that past oral contraceptive use significantly lowers the risk of ovarian and uterine cancers later in life, this new observation in monkeys may shed light on the mechanism behind the cancer-protective effect of the treatment. Past oral contraceptive use appears to result in a long-term change in the way the monkeys' bodies process hormones. While researchers don't yet understand the precise mechanism by which hormone levels are being affected, they do know that both the level of estrogen in the blood and the amount of estrogen being excreted in urine are lowered with past oral contraceptive use, which may mean that the oral contraceptive use is somehow leading to a diminished synthesis of estrogen.

The study appears in this month's issue of Cancer Epidemiology, Biomarkers and Prevention.

"Hormone exposure has long been known to be important in cancer risk," said J. Mark Cline, D.V.M., Ph.D., and senior researcher on the project. "These effects are robust, and we believe this discovery could be translated fairly quickly into a study in women. If our results are confirmed to also occur in women, they could change the way we look at oral contraceptives and cancer risk," added Cline, a professor of pathology and comparative medicine.

With funding from the National Institutes of Health, researchers began with 181 premenopausal cynomolgus monkeys and followed them for seven years in a study designed to look at hormone effects on many aspects of female health.

Half of the monkeys were given a birth control treatment of triphasic estrogen and progestin, marketed by Wyeth Pharmaceuticals as TriphasilTM, for 26 months. At the end of the premenopausal phase of the study, the animals underwent surgery to have their ovaries removed, making them surgically menopausal.

The postmenopausal monkeys were then divided into three dietary intervention groups to evaluate the effects of soy on hormone metabolism.

Urine samples were collected from each monkey during the 35th and 36th months of the postmenopausal phase of the study and frozen for subsequent analysis of metabolite concentrations.

Lab results showed that the premenopausal use of oral contraceptives resulted in significantly lower levels of most estrogen metabolites three years after surgical menopause. Among the most abundant metabolites, percent changes ranged from a 25 percent reduction in E1 to a 50 percent reduction in 2OHE1 with oral contraceptive administration. Postmenopausal dietary isoflavones induced fewer significant effects on postmenopausal estrogen metabolite concentrations.

"The magnitude and persistence of oral contraceptive effect really surprised us," said Cline, a diplomate of the American College of Veterinary Pathologists. "It tells us that there may be a new and potentially strong cancer-protective mechanism at work. This could open new doors of inquiry in the field."


'/>"/>

Contact: Jessica Guenzel
jguenzel@wfubmc.edu
336-716-3487
Wake Forest University Baptist Medical Center
Source:Eurekalert

Related biology news :

1. Risk of common vaginal infection linked to preterm birth appears higher for blacks
2. Birth records hold pancreatic cancer clue
3. Researchers find evidence linking stress caused by the Sept. 11 disaster with low birth weights
4. Birth of an iceberg
5. The birth and death of dopamine neurons: A new model for neurodegeneration
6. Certain diseases, birth defects may be linked to failure of protein recycling system
7. New folic acid seal helps women choose enriched grain foods to help prevent birth defects
8. Immunosuppressant further linked to birth defects
9. Northern right whales head south to give birth, leave genetic fingerprints with NOAA researchers
10. Deadly genetic disease prevented before birth in zebrafish
11. Birth of an enzyme
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/2/2016)... 2016 The Department of Transport Management ... 44 million US Dollar project, for the , ... Personalization, Enrolment, and IT Infrastructure , to ... and implementation of Identity Management Solutions. Numerous renowned international vendors ... Decatur was selected for the most compliant and ...
(Date:5/24/2016)... care by providing unparalleled technology to leaders of the medical imaging industry.  As such, ... to the range of products distributed by Ampronix. Photo - http://photos.prnewswire.com/prnh/20160524/371420 ... ... ... With ...
(Date:5/9/2016)... 9, 2016 Elevay is currently ... expanding freedom for high net worth professionals seeking travel ... globally connected world, there is still no substitute for ... duplicate sealing your deal with a firm handshake. This ... taking advantage of citizenship via investment programs like those ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... ... findings on what they believe could be a new and helpful biomarker for ... research. Click here to read it now. , Biomarkers are components ...
(Date:6/27/2016)... 27, 2016  Liquid Biotech USA ... of a Sponsored Research Agreement with The University ... (CTCs) from cancer patients.  The funding will be ... correlate with clinical outcomes in cancer patients undergoing ... then be employed to support the design of ...
(Date:6/24/2016)... ... ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension of 8.5 ... end machines that use the more unconventional z-dimension of 20mm. Z-dimension or ... the cuvette holder. , FireflySci has developed several Agilent flow cell product lines ...
(Date:6/23/2016)... , June 23, 2016   Boston Biomedical ... novel compounds designed to target cancer stemness pathways, ... been granted Orphan Drug Designation from the U.S. ... of gastric cancer, including gastroesophageal junction (GEJ) cancer. ... designed to inhibit cancer stemness pathways by targeting ...
Breaking Biology Technology: