Navigation Links
Scientists learn more about how kidneys fail and how new drugs may intervene

Scientists are learning more about how protein gets in the urine when the kidneys begin to fail and how a new drug blocks it.

"We have known for a long time that renal failure comes with protein in your urine, especially in diabetes," said Dr. David Pollock, renal physiologist at the Medical College of Georgia Vascular Biology Center. It's also known that a new class of drugs called endothelin A receptor antagonists reduce protein in the urine.

New research published in the journal Hypertension connects the two, providing more information about how new drugs under study for kidney failure work.

The scientists have shown in rats that increased levels of the peptide endothelin 1 characteristic of conditions such as diabetes and high-salt diets increase the permeability of tiny kidney filters. The filters recycle key components such as red and white blood cells and proteins, including albumin, that help keep blood vessels from leaking fluid.

The increased permeability causes the proteins to be eliminated in the urine, resulting in a double whammy that likely includes generalized body swelling and further kidney damage. "Without albumin, the fluid just goes into your tissue," Pollock said.

"This filter, which is like cheesecloth, gets damaged in kidney failure and so you get more of these proteins in your urine. Filters start scarring over, you lose the nephron (the filter and its associated kidney cells) and so the kidneys slowly die," he said.

And that's just part of the damage. High endothelin levels also trigger inflammation, sending out proinflammatory molecules that attract inflammatory cells like white blood cells and macrophages to the kidneys, MCG researchers have shown. They also have shown that endothelin A receptor antagonists reduce this inflammatory response.

"There has been no drug that really targets diabetic nephropathy," said Mohamed A. Saleh, MCG graduate student and the study's first author. The study provides more scientific evidence that the new endothelin A receptor antagonists may be the first class of drugs to fit that bill, said Saleh, noting that his native Egypt, like the United States, has an increasing problem with diabetes.

The positive results were achieved without affecting blood pressure, the scientists noted. Endothelin receptor antagonists are known to have health benefit but precisely why was an unknown, said Pollock, corresponding author on the study. "A lot of people thought they just lower blood pressure and anything that lowers blood pressure is going to make your kidneys feel better," he said.

Endothelin 1 has A and B receptors and whether the peptide hurts or helps generally depends on which receptor it activates. The B receptor is considered the good guy, helping the kidney eliminate excess sodium, for example. The A receptor is generally considered a trouble maker that interferes with sodium excretion, constricts blood vessels and promotes inflammation.

The MCG scientists want to compare A inhibitors to another new class of drugs that blocks both the A and B receptors.


Contact: Toni Baker
Medical College of Georgia

Related biology news :

1. Jefferson scientists deliver toxic genes to effectively kill pancreatic cancer cells
2. Scientists identify novel inhibitor of human microRNA
3. Argonne scientists peer into heart of compound that may detect chemical, biological weapons
4. MU scientists go green with gold, distribute environmentally friendly nanoparticles
5. Scientists identify gene that may contribute to improved rice yield
6. Scientists discover why a mothers high-fat diet contributes to obesity in her children
7. MU scientists see how HIV matures into an infection
8. Earth scientists keep an eye on Texas
9. Thinking it through: Scientists call for policy to guide biofuels industry toward sustainability
10. Scientists identify a molecule that coordinates the movement of cells
11. Scientists Find new migratory patterns for Mediterranean and Western Atlantic bluefin tuna
Post Your Comments:
Related Image:
Scientists learn more about how kidneys fail and how new drugs may intervene
(Date:10/29/2015)... , Oct. 29, 2015  Connected health pioneer, ... driving the explosion of technology-enabled health and wellness, and ... new book, The Internet of Healthy Things ... sensors or smartphones even existed, Dr. Kvedar, vice president, ... of health care delivery, moving care from the hospital ...
(Date:10/27/2015)... , October 27, 2015 ... Automated Semantic Gaze Mapping technology (ASGM) automatically maps data ... Eye Tracking Glasses , so that they can ... --> Munich, Germany , October ... automatically maps data from mobile eye tracking videos created ...
(Date:10/26/2015)... NEWARK, Calif. , Oct. 26, 2015  Delta ... convenient biometric authentication to mobile and PC devices, announced ... Fujitsu,s smartphone, the arrows NX F-02H launched by NTT ... arrows NX F-02H is the second smartphone to include ... this technology in ARROWS NX F-04G in May 2015, ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , ... November 24, 2015 , ... ... healthy metabolism. But unless it is bound to proteins, copper is also toxic ... (NIH), researchers at Worcester Polytechnic Institute (WPI) will conduct a systematic study of ...
(Date:11/24/2015)... -- --> --> ... Market by Product & Services (Primer, Probe, Custom Oligos, ... End-User (Research, Pharmaceutical & Biotech, Diagnostic Labs) - Global ... expected to reach USD 1,918.6 Million by 2020 from ... 10.1% during the forecast period. Browse 183 ...
(Date:11/24/2015)... 24, 2015 --> ... report released by Transparency Market Research, the global non-invasive ... CAGR of 17.5% during the period between 2014 and ... Global Industry Analysis, Size, Volume, Share, Growth, Trends and ... testing market to reach a valuation of US$2.38 bn ...
(Date:11/24/2015)... ... 2015 , ... In harsh industrial processes, the safety of ... can represent a weak spot where leaking process media is a possible hazard. ... , which are designed to tolerate extreme process conditions. They combine rugged design ...
Breaking Biology Technology: