Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Common genetic mutation increases sodium retention, blood pressure

30.05.2012
Nearly 40 percent of the small adrenal tumors that cause big problems with high blood pressure share a genetic mutation that causes patients to retain too much sodium, researchers report.

The study of 47 human, benign adrenal gland tumors also showed a mutation of the gene KCNJ5 is twice as likely to occur in women – 71 versus 29 percent – as it points to potential new treatments for some patients who don't respond to current hypertension regimens, said Dr. William E. Rainey, Scientific Director of the Adrenal Center at Georgia Health Sciences University.

Addititionally, when scientists put the mutated gene into an adrenal cell, it immediately starts producing the sodium-retaining hormone aldosterone. "We found it turned on a whole series of genes that cause the cell to produce aldosterone," Rainey said.

Typically, KCNJ5 appears to help normalize levels of the sodium-retaining hormone aldosterone by regulating how much potassium is pumped in and out of aldosterone-producing cells on the outer layer of the adrenal glands. Abnormal protein produced by the mutated gene alters the cells' electrical status.

"When this gene has a mutation, the cells lose control and just start producing aldosterone all the time," said Rainey, corresponding author of the study in the Journal of Clinical Endocrinology and Metabolism.

"The combination of too much salt and too much of this hormone leads to high blood pressure and tissue damage," said Rainey. He notes that the vast majority of the 311 million Americans consume too much salt, even if they never pick up a salt shaker, because of high content in breads, processed and fast foods and the like. An estimated 33 percent of Americans are hypertensive and an estimated 1 in 10 have adrenal problems as the cause.

A 2011 study led by Yale University and published in the journal Science showed that the tumors had a KCNJ5 mutation. GHSU researchers, along with colleagues at University of Michigan Medical School, Ann Arbor; University of Torino and University of Padova, Italy; University of Texas Southwestern Medical Center, Dallas; and Keio University,Tokyo linked the gene to aldosterone production.

Now the GHSU Adrenal Center is moving forward with studies to determine why women with adrenal tumors have more of the mutated gene – Rainey suspects it's estrogen-related. They also want to know if any of the dozen potassium channel inhibitors already on the market for heart and other disorders can help these patients as well.

Rainey said the gene mutation is one that occurs after birth – when most mutations occur – and the cause is unknown. About half the people who produce too much aldosterone have tumors, which tend to affect only one of the 2-by-1-inch glands that sit like hats on top of the two kidneys and surgical removal typically fixes their problem. Unexplained enlargement of both glands likely also has a genetic basis and may be medically managed, Rainey said.

One of the many goals of the GHSU Adrenal Center, one of a handful of multidisciplinary centers in the nation, is to better define genes which can result in whole families being impacted. To date, only three genes are known to contribute to the familial form. Aldosterone excess, by whatever means, also is suspected when people under age 40 become hypertensive for no other obvious reason.

The adrenals are extremly efficient glands, producing three additional hormone groups that help maintain homeostasis including cortisol needed for glucose/carbohydrate metabolism, weak sex steroids that likely are the major source of androgens, or male hormones, in women; and the fight or flight hormones epinephrine and norepinephrine. In the event both glands are removed, the vital hormones must be supplemented, Rainey said.

Patients typically come to the GHSU Adrenal Center with unexplained hypertension that isn't responding to traditional therapy. "They are typically on three or four medications and their blood pressure is still not under control," said Dr. Michael A. Edwards, Clinical Director of the Adrenal Center and Chief of the MCG Section of Minimally Invasive and Digestive Diseases Surgery. Computerized tomography done for other reasons can detect over-sized glands or tumors that may be the culprit.

For more information, visit http://www.mcghealth.org/adrenal/GhsuContentPage.aspx?nd=367

Toni Baker | EurekAlert!
Further information:
http://www.georgiahealth.edu

More articles from Health and Medicine:

nachricht Why might reading make myopic?
18.07.2018 | Universitätsklinikum Tübingen

nachricht Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>