Fom Jan. 2005, so why is there so little work being done to stop this cascade of death? This research from 2003 suggests that maybe glutamate poisoning is not really the factor so why does something published in 2005 still refer to it.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=35484&CultureCode=en
Medical Research Council (MRC) scientists, in collaboration with
colleagues from British and Italian universities, have unveiled a
mechanism that causes the death of brain cells (neurons) in stroke. The
discovery may help explain why some therapy approaches for stroke have
been unsuccessful and identifies potential research avenues for the
development of new treatments for stroke and other degenerative brain
diseases.
Stroke is a consequence of an abrupt interruption of blood flow to
the brain. When the blood supply stops, the nerve cells that are
directly deprived of oxygen quickly die and release the chemicals that
they use to communicate with each other. One of these neurotransmitters –
glutamate – spreads to surrounding cells and sets off a process called
excitotoxicity, causing much more widespread cell death. Glutamate
triggers a flood of calcium ions into the cells and, for reasons not
previously understood, the level of calcium continues to rise and this
kills the neurons.
The new research, carried out at the MRC’s Toxicology Unit in
Leicester, studied the mechanism of calcium overload in neurons after
reduction in blood supply to areas of the rat brain. The initial flood
of calcium activates enzymes called calpains, which break down the
proteins in the cell membrane that normally pump calcium out of the
cell.
For many years research has concentrated on trying to block the
inflow of calcium, in the hope of preventing brain damage in stroke. But
the new findings suggest that the main defect is in the removal of
calcium from neurons. This opens up new opportunities for the
development of drugs to reduce nerve cell death, not only in stroke but
also in degenerative brain disorders.
Each year over 130,000 people suffer from a stroke in England and
Wales and acute stroke remains a major cause of death or severe chronic
disability.
Research group leader and Unit Director, Professor Pierluigi Nicotera said:
“Work at the MRC Toxicology Unit has unveiled the process that
destroys the primary line of defence against calcium accumulation in the
brain, which explains the build-up of lethal calcium levels in neurons.
“This is an exciting discovery because these findings go some way to
explaining why therapy aimed solely at decreasing calcium entry in
brain cells has been unsuccessful. This research identifies potential
novel targets for treatment of stroke and other neurodegenerative
diseases. The findings may lead to new drugs which will treat these
conditions successfully.”
Professor Colin Blakemore, Chief Executive of the Medical Research Council, said:
“This research is an important step forward for the development of
new and more effective treatments for stroke – one of the most common
conditions affecting the elderly in the UK. And, as the UK’s elderly
population continues to grow, so does the importance of targeting the
diseases that are common in later life.
“Through the creation of the new UK Clinical Research Collaboration,
the MRC will work in partnership with the NHS, medical charities and
industry to speed up the development of new treatments so that more
patients can benefit more quickly form the latest scientific advances.”
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