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 A whole-body approach to understanding chemosensory cells
13.12.2017 | Tokyo Institute of Technology

nachricht Research reveals how diabetes in pregnancy affects baby's heart
13.12.2017 | University of California - Los Angeles Health Sciences

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>