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 The genes are not to blame
20.07.2018 | Technische Universität München

nachricht Targeting headaches and tumors with nano-submarines
20.07.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>