Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blood flow in Alzheimer's disease

29.07.2009
Researchers have discovered that the enzyme, endothelin converting enzyme-2 (ECE-2), may cause the decrease in blood flow in the brain seen in Alzheimer's disease and contribute to progression of the disease.

The study by Jennifer Palmer, BRACE/Reverend Williams PhD Scholar and colleagues at the University of Bristol's Dementia Research Group is published in the current issue [July 2009] of the American Journal of Pathology.

Alzheimer's disease is the most common form of dementia, affecting over half a million people in the UK - a figure expected to double in the next 20 years. Aâ peptide, which accumulates in the brain of Alzheimer's disease patients, is thought to lead to narrowing of the blood vessels and reduction of blood flood in the brain. ECE-2 may contribute to the disease by converting an inactive precursor to endothelin-1, which constricts blood vessels and further reduces blood flow.

Jennifer Palmer said: "Our findings raise the possibility that drugs that can block the actions of endothelin-1 and which are already licensed for treating other diseases may also be of benefit for the treatment of Alzheimer's disease."

Much of the funding for Jennifer Palmer's work comes from Bristol-based charity BRACE. The charity's Chief Executive, Mark Poarch added: "This is real progress and opens up new areas for research. It is also good news for the thousands of local people who have raised money to try to beat Alzheimer's. BRACE is stepping up its fundraising to help scientists press on and find a cure."

The researchers had been studying ECE-2 in human brain tissue that was donated to the South West Dementia Brain Bank at the University of Bristol because the enzyme is also able to break down Aâ peptide, which accumulates in Alzheimer's disease. They found that ECE-2 was markedly elevated in Alzheimer's disease. ECE-2 was particularly abundant in nerve cells in a part of the brain that is critical for memory and is severely affected by Alzheimer's disease.

The increase in ECE-2 in Alzheimer's disease is not simply a by-product of nerve cell damage. When the researchers looked at brain tissue from patients with a different type of dementia (vascular dementia), ECE-2 levels were normal – no different from the levels in brain tissue from elderly people without dementia. Further studies showed that the increase seen in Alzheimer's disease of ECE-2 could not be explained by differences in age, gender or time to brain removal after death between the various groups of patients that were studied.

To investigate why ECE-2 might be specifically elevated in Alzheimer's disease, the researchers then examined nerve cells that were grown in a laboratory. They showed that addition of Aâ caused these nerve cells to increase their production of ECE-2. The findings indicate that nerve cells produce more ECE-2 when they are exposed to Aâ.

In the normal brain, blood flow responds to nerve cell activity. If nerve cell activity in a particular part of the brain increases, so does the supply of blood that is needed to meet the extra demand for nutrients such as glucose and oxygen. If this demand is not met, as can happen in Alzheimer's disease, the nerve cells may not function normally and may even sicken and die.

Although the elevated ECE-2 in Alzheimer's disease may help to break down amyloid beta, it may also cause the decrease in blood flow in the brain, through the production of too much endothelin-1. This may have important implications for treatment. Drugs are available that can block the actions of endothelin-1 and which have been shown to treat some other diseases in which excess endothelin-1 reduces blood flow. The findings raise the possibility that these drugs may also be of benefit for the treatment of Alzheimer's disease.

Joanne Fryer | EurekAlert!
Further information:
http://www.bristol.ac.uk

Further reports about: Alzheimer BRACE ECE-2 blood flow blood vessel brain tissue dementia nerve cell

More articles from Health and Medicine:

nachricht New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute

nachricht Distrust of power influences choice of medical procedures
01.08.2018 | 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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>