Featured Research

from universities, journals, and other organizations

Abnormal activation of a protein may explain deadly link between high salt intake and obesity

Date:
September 19, 2011
Source:
American Physiological Society
Summary:
Research suggests that high dietary salt intake and obesity work together to trigger an abnormal activation of a cellular protein called Rac1.

Dietary salt intake and obesity are two important risk factors in the development of high blood pressure. Each packs its own punch, but when combined, they deliver more damage to the heart and kidneys than the sum of their individual contributions. Discovering the molecular mechanisms behind this lethal synergy has presented a challenge to scientists, but research led by Toshiro Fujita, MD, professor and chairman of the Department of Internal Medicine and chief of the Department of Nephrology and Endocrinology at the University of Tokyo, suggests that high dietary salt intake and obesity work together to trigger an abnormal activation of a cellular protein called Rac1.

How Obesity and a High-Salt Diet Team Up

Dr. Fujita's team studied the effects of a high-salt diet in rats bred to have high blood pressure and different levels of blood pressure sensitivity to salt. When obese "salt-sensitive" rats were fed a high-salt diet, the team found that Rac1 activated the mineralocorticoid receptor (MR) on the rats' kidney cells. This receptor is normally activated by the hormone aldosterone. When turned on, MR leads to the expression of a protein called epithelial sodium channel (ENaC) and an enzyme called the sodium pump. Both of these substances promote the reabsorption of salt, which causes the body to retain fluid and results in high blood pressure. This is the first time scientists have seen Rac1 usurp aldosterone's role in activating MR in the regulation of blood pressure. The protein's usual duties entail regulating an array of cellular events such as cell growth.

The team made the discovery when attempting to treat the obese, hypertensive rats with drugs designed to block MR activation and inhibit Rac1. When Rac1 inhibitors were successful in lowering the rats' blood pressure, the team knew they had discovered a mechanism by which obesity and a high-salt diet team up to wreak havoc on blood pressure and the kidneys.

Importance of the Findings

According to Dr. Fujita, the team's findings carry important implications for the treatment of hypertension. "Our data indicate that the Rac1-mediated pathway in the kidneys can be an alternative therapeutic target for salt-sensitive hypertension and salt-mediated kidney injury," he said. "Based upon our results, we can speculate that Rac1 in the kidneys regulates salt susceptibility of blood pressure, and that Rac1 inhibitors, as well as MR antagonists, may be effective in the treatment of salt-sensitive hypertension."

Presentation

Dr. Fujita will discuss the team's research in his presentation titled, "Aberant Rac1-MR Pathway in Salt-Sensitive Hypertension and Metabolic Syndrome" at the upcoming 7th International Symposium on Aldosterone and the ENaC/Degenerin Family of Ion Channels, being held September 18-22 in Pacific Grove, Calif. The conference is sponsored by the American Physiological Society.


Story Source:

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


Cite This Page:

American Physiological Society. "Abnormal activation of a protein may explain deadly link between high salt intake and obesity." ScienceDaily. ScienceDaily, 19 September 2011. <www.sciencedaily.com/releases/2011/09/110919104802.htm>.
American Physiological Society. (2011, September 19). Abnormal activation of a protein may explain deadly link between high salt intake and obesity. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2011/09/110919104802.htm
American Physiological Society. "Abnormal activation of a protein may explain deadly link between high salt intake and obesity." ScienceDaily. www.sciencedaily.com/releases/2011/09/110919104802.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Fauci: Ebola Protocols to Focus on Training

Fauci: Ebola Protocols to Focus on Training

AP (Oct. 20, 2014) Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, says he expects revised CDC protocols on Ebola to focus on training, observation and ensuring health care workers are more protected. (Oct. 20) Video provided by AP
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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