Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New pathway for treating hypertension-related kidney failure studied

20.06.2002


A Medical College of Georgia researcher is tracing the pathway that leads people with hypertension to kidney damage and possible kidney destruction.



He’s found a key vasodilator that is degraded in hypertension and the potential for developing drugs that prevent organ damage in these patients.

"In every form of hypertension, except pulmonary hypertension, which is limited to the lungs, there is a change in kidney function so the kidneys cannot excrete the proper amount of salt and water at a normal blood pressure," said Dr. John D. Imig, renal vascular biologist at the MCG Vascular Biology Center.


"In fact, a change in kidney function has to occur before you can get the increase in blood pressure," Dr. Imig said. Indeed, researchers such as Dr. Imig are finding increasing evidence that the kidneys, which regulate sodium and water volume in the body, are a primary controller of blood pressure . "If you give a patient with hypertension who is on kidney dialysis a good kidney from a normotensive individual, all of the sudden, (his) blood pressure is controlled," he said.

Whichever comes first, hypertension-related kidney disease results in a breakdown in the extensive network where thousand of tiny filters called glomeruli connect to tubules that carry excess salt, water and toxins out of the kidneys so they can be excreted in the urine. As Dr. Imig looks over an image of a damaged kidney, the sclerosis and inflammation is readily apparent. Tiny glomeruli eventually die and the kidneys stop working.

Despite the large number of antihypertensive drugs on the market, the incidence of kidney damage and end-stage renal disease in these patients keeps going up, Dr. Imig said. Most of the drugs, in fact, do target the kidneys. Diuretics reduce the fluid and salt volume they must handle and ACE inhibitors and angiotensin receptor blockers block the action of the vasoconstrictor, angiotenin 2, which is released by the kidneys.

Dr. Imig has helped identify a system within the kidneys that is a target for still newer drugs that could work with these other therapies – particularly those that impact angiotensin 2 – and reduce damage to kidneys and possibly other major organs such as the heart and brain.

He’s looking at arachidonic acid and its metabolites, particularly one called epoxyeicosatrienoic acids, or EETs, that not only relax blood vessels but also reduce inflammation. Arachidonic acid is a fatty acid inside cell membranes that can be released in a number of ways and for multiple functions. In the kidneys, it increases blood flow by relaxing the smooth muscles of the blood vessels and also works as an anti-inflammatory agent.

In kidney disease, EETs are broken down by an enzyme, soluble epoxide hydrolase, rendering EETs ineffective. Levels of this enzyme somehow increase in hypertension. Dr. Imig is working with Dr. Bruce Hammock, an entomologist and chemist at the University of California at Davis, who has developed an inhibitor to the enzyme. They’ve shown, at least in animal models, that when soluble epoxide hydrolase is blocked, blood pressure goes down and kidney function improves. Dr. Imig also is working with a pharmaceutical company on another inhibitor of this pathway.

He’s also working with Dr. J.R. Falck, a chemist at the University of Texas Southwestern, to develop drugs, called mimetics, which work like EETs. "EETs are very unstable and hard to use; they are short-lived like nitric oxide, another potent vasodilator. We are trying to find ways to modify this structure so we can give it to a patient," Dr. Imig said.

"We know EETs are there and that they are decreased in hypertension. If you look at a kidney destroyed by hypertension, there is still some but it is decreased. And we know that if you increase EET levels in hypertension, you help blood vessels function in the kidneys," the young researcher said.

"It may be that a combination of an ACE inhibitor or angiotensin receptor blocker with soluble epoxide hydrolase or one of these synthetic EETs may prevent end-stage renal disease," he said. "That’s our overall goal: to keep people from going on dialysis."


Dr. Imig’s research is funded by the National Institutes of Health and the American Heart Association.


Toni Baker | EurekAlert!

More articles from Health and Medicine:

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

nachricht Better equipped in the fight against lung cancer
16.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>