Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Growth factor promotes new blood routes in rat brain, which may prevent stroke

01.07.2003


Injections of a stimulant agent into rat brains expanded blood vessels and improved blood flow, a finding that may lead to a new, non-invasive way to prevent stroke, researchers reported in today’s rapid access issue of Circulation: Journal of the American Heart Association.



Rats treated with the growth-promoting substance granulocyte macrophage-colony stimulating factor (GM-CSF) had almost twice as much arteriogenesis, the expansion of a brain artery, after one week compared to rats given saline solution. The increase was associated with improved circulation and accumulation of cells that are thought to play a key role in artery development.

“To the best of our knowledge, this is the first report of stimulation of arteriogenesis in the brain,” say co-lead authors Ivo R. Buschmann, M.D., and Hans-Jörg Busch, M.D. Both are investigators in the Research Group for Experimental and Clinical Arteriogenesis at Albert Ludwigs University in Freiburg, Germany.


The findings suggest that growth-stimulating substances may be a novel alternative to other stroke prevention strategies, which tend to emphasize surgery and other invasive techniques that improve blood flow to the brain, the researchers say.

Growth-stimulating factors have induced angiogenesis – the growth and expansion of tiny vessels called capillaries in the immediate vicinity of reduced blood flow – in patients with coronary artery disease. However, “angiogenesis studies have failed to improve outcome in stroke,” the researchers say.

Buschmann and Busch took a different approach. They tried to induce arteriogenesis by transforming pre-existing (collateral) arteries that were unused and located away from the blockage into functioning blood-carrying vessels capable of taking over for the blocked vessels. Arteriogenesis is an effective natural mechanism to compensate for blood flow because of blocked arteries in the heart, periphery or brain, Buschmann says.

In laboratory experiments, growth factors have stimulated collateral circulation in the extremities and in the coronary circulation. Recently, GM-CSF treatment induced arteriogenesis in a small group of patients with coronary artery disease.

To evaluate the potential of GM-CSF to stimulate arteriogenesis in the brain, Buschmann and Busch induced arterial obstructions that reduced blood flow to the brain of rats, and then injected them with the growth factor. Treatment continued for seven or 21 days. A second group of rats received saline over the same period.

The researchers studied the effects of treatment on expansion of the posterior cerebral artery (PCA), an artery that originates in the back of the brain and was not near the blocked arteries. In saline-treated rats the diameter of the PCA increased by 39 percent during the three weeks. The artery expanded much faster – 72 percent at the end of one week – in rats treated with GM-CSF. The growth factor-related arteriogenesis was associated with other evidence of improved blood flow, such as the ability to increase flow in response to carbon dioxide (a signal for reduced blood supply) and accumulation of macrophages, cells that are thought to be involved in the growth of collateral arteries.

“To the best of our knowledge, this is the first study that demonstrates an improvement of brain hemodynamic parameters (blood flow) after such treatment,” the researchers state.

Co-authors are Günter Mies, M.D., and Konstantin-Alexander Hossmann, M.D.

Carole Bullock | American Heart Association
Further information:
http://www.americanheart.org/
http://www.americanheart.org/presenter.jhtml;jsessionid=OA4I0G2TMNRAJWFZOAHCCZQ?identifier=3013235

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: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

X-ray scattering shines light on protein folding

10.07.2020 | Life Sciences

Looking at linkers helps to join the dots

10.07.2020 | Materials Sciences

Surprisingly many peculiar long introns found in brain genes

10.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>