Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover new mechanism for clearing blockages from smallest blood vessels

27.05.2010
Researchers at Northwestern University Feinberg School of Medicine have identified in mice a previously unknown protective mechanism by which the smallest blood vessels remove blood clots and other blockages from the brain. The findings provide insights into mechanisms that may be involved in age-related cognitive decline, Alzheimer's disease and recovery from stroke.

These findings were described in the May 27 issue of Nature by Jaime Grutzendler, M.D., and colleagues. The study was supported by the National Institute on Aging (NIA), part of the National Institutes of Health.

Uninterrupted blood flow is critical for brain function, and the brain has developed various mechanisms to maintain it. Blockages in the smallest blood vessels can be cleared by processes that disintegrate or wash them out. However, not all blockages are cleared completely. Persistent blockage can reduce or stop blood flow, limiting the supply of oxygen and nutrients to the surrounding tissue and nerve cells. This, in turn, can lead to impaired communications between nerve cells and ultimately cell death.

The researchers used a newly developed imaging technique that can view the smallest blood vessels, known as microvessels, in the brains of living mice. They found that two to seven days after a blockage in brain microvessels, the cells lining the blood vessel wall engulf the remaining portion of the blockage, encapsulate it, seal it off from the interior of the blood vessel and finally expel the blocking material outside of the vessel. As a result of this process, blood flow is restored to the affected area. (See graphic below.)

"These are intriguing findings," said NIA Director Richard J. Hodes, M.D. "They open new avenues of basic research that may increase our understanding of how microvessels are maintained in the brain and throughout the body."

The research team demonstrated that this complex protective mechanism involves the activity of an enzyme, matrix metalloprotease 2/9, which breaks down large proteins and is known to play a role in blood vessel development and in stroke.

The researchers also found that the ability to move the blockage out of the blood vessel diminished with age. Young mice (age 4 months) were able to clear blockages more quickly and thoroughly than older mice (age 22 months). The incomplete removal of blockages in the brains of older mice led to a prolonged shortage of oxygen to the surrounding nerve cells and damaged the connections between nerve cells in the vicinity of the obstructed blood vessels.

"The reduced efficiency of this protective mechanism in the older brain and its effect on the function of nerve cells in the brain may significantly contribute to age-related cognitive decline," said Suzana Petanceska, Ph.D., of the Neurobiology of Aging Branch in NIA's Division of Neuroscience, which funded the research. "This may also be part of the mechanism by which vascular risk factors such as high blood pressure and diabetes increase the risk of Alzheimer's disease with age."

The NIA leads the federal effort supporting and conducting research on aging and the medical, social and behavioral issues of older people. For more information on research and aging, go to www.nia.nih.gov.

The NIH—The Nation's Medical Research Agency—includes 27 institutes and centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Barbara Cire | EurekAlert!
Further information:
http://www.nih.gov

More articles from Health and Medicine:

nachricht Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign

nachricht Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>