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 July 31, 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 July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) — Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) — Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Newsy (July 30, 2014) — The Peace Corps is one of several U.S.-based organizations to pull workers out of West Africa because of the Ebola outbreak. Video provided by Newsy
Powered by NewsLook.com
Weather Kills 2K A Year, But Storms Aren't The Main Offender

Weather Kills 2K A Year, But Storms Aren't The Main Offender

Newsy (July 30, 2014) — Health officials say 2,000 deaths occur each year in the U.S. due to weather, but it's excessive heat and cold that claim the most lives. 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