Featured Research

from universities, journals, and other organizations

Kidney damage and high blood pressure: Faulty filtration allows detrimental enzymes to wreak havoc on fluid balance, research suggests

Date:
September 23, 2011
Source:
American Physiological Society
Summary:
Scientists have now begun to understand kidney damage on a cellular level and how the activity of certain molecules in damaged kidneys contributes to salt and water retention in nephrotic syndrome. Several new insights in this area of research are presented at an upcoming meeting.

The kidney performs several vital functions. It filters blood, removes waste products from the body, balances the body's fluids, and releases hormones that regulate blood pressure. A number of diseases and conditions can damage the kidney's filtration apparatus, such as diabetes and immune disorders. This damage leads to a condition called nephrotic syndrome, which is characterized by protein in the urine, high cholesterol and triglycerides, and swelling (edema). People with nephrotic syndrome retain salt and water in their bodies and develop swelling and high blood pressure as a result.

Scientists have now begun to understand kidney damage on a cellular level and how the activity of certain molecules in damaged kidneys contributes to salt and water retention in nephrotic syndrome. Several new insights in this area of research will be presented at the7th International Symposium on Aldosterone and the ENaC/Degenerin Family of Ion Channels, being held September 18-22 in Pacific Grove, Calif. The meeting is sponsored by the American Physiological Society.

Faulty Filtration

The kidneys are marvels of filtration, processing roughly 150 to 200 quarts of blood each day through tiny structures called nephrons. There are about 1 million nephrons per kidney, and each nephron consists of a filtering unit of blood vessels called a glomerulus, which is attached to a tubule. Filtered blood enters the tubule, where various substances are either added to or removed from the filtrate as necessary, and most of the filtered sodium and water is removed. The filtrate that exits the tubule is excreted as urine.

In nephrotic syndrome, a damaged filtration barrier allows substances that are not normally filtered to appear in the filtrate. One of these substances is the protein plasminogen, which is converted in kidney tubules to the protease plasmin. In their research, Thomas R. Kleyman, Professor of Medicine and of Cell biology and Physiology at the University of Pittsburgh School of Medicine and the Symposium's co-organizer, and Ole Skøtt, Professor of Physiology and Pharmacology and Dean at the University of Southern Denmark in Odense, independently found that plasmin plays a role in activating the epithelial sodium channel (ENaC) on cells in the nephron. ENaC is a protein embedded in cell membranes that facilitates the absorption of filtered sodium from tubules. When ENaC is becomes overactive, excessive absorption of filtered sodium may lead to sodium and water retention.

According to Dr. Kleyman, these findings provide an explanation of how damage to the glomeruli in the kidney's nephrons leads to edema and high blood pressure. Dr. Kleyman explains: "When plasminogen is cleaved, it can act on several targets. One of those targets is ENaC. Another is the protein prostasin, which, once cleaved, will activate ENaC, as well."

Dr. Kleyman noted the implications these findings have for treating edema and high blood pressure in patients suffering from nephrotic syndrome. "This is important because if plasmin activates ENaC, it suggests that targeting ENaC in the kidneys with ENaC inhibitors may be a treatment option."


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. "Kidney damage and high blood pressure: Faulty filtration allows detrimental enzymes to wreak havoc on fluid balance, research suggests." ScienceDaily. ScienceDaily, 23 September 2011. <www.sciencedaily.com/releases/2011/09/110922134615.htm>.
American Physiological Society. (2011, September 23). Kidney damage and high blood pressure: Faulty filtration allows detrimental enzymes to wreak havoc on fluid balance, research suggests. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2011/09/110922134615.htm
American Physiological Society. "Kidney damage and high blood pressure: Faulty filtration allows detrimental enzymes to wreak havoc on fluid balance, research suggests." ScienceDaily. www.sciencedaily.com/releases/2011/09/110922134615.htm (accessed August 20, 2014).

Share This




More Health & Medicine News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
101-Year-Old Working Man Has All The Advice You Need

101-Year-Old Working Man Has All The Advice You Need

Newsy (Aug. 19, 2014) — Herman Goldman has worked at the same lighting store for almost 75 years. Find out his secrets to a happy, productive life. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) — Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com
American Ebola Patient Apparently Improving, Outbreak Is Not

American Ebola Patient Apparently Improving, Outbreak Is Not

Newsy (Aug. 19, 2014) — Nancy Writebol, an American missionary who contracted Ebola, is apparently getting better, according to her husband. The outbreak, however, is not. Video provided by Newsy
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:
from the past week

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