Discovery could block blood clots

Scientists have found a potential way to prevent blood clots which can cause heart attacks.

They believe the discovery could aid the development of better heart attack prevention and treatment.

The key is to remove a particular protein - PKC alpha - fromspecialist blood cells called platelets which play a key role in theformation of clots.

The University of Bristol study, carried out in mice, appears in the Journal of Clinical Investigation.

We are excited to have made a step in the right direction towards the development of a new family of potentially useful anti-clotting medicines for heart patients
Professor Alastair Poole
University of Bristol Blood clots perform an essential function, limiting blood loss from a wound.

However, when they form in diseased arteries feeding the heart theycan be life-threatening, causing a heart attack in 146,000 people inthe UK every year.

Current anti-clotting medicines, such as aspirin, reduce therisk of heart attack - but in some people can also cause excessive anddangerous bleeding.

Platelets are small cells in the blood that sense when a blood vessel has been damaged.

They rapidly become very sticky, and form a protective plaster over the site of damage.

In a patient with heart disease, fatty plaques build up in the walls of the arteries feeding the heart.

If an artery ruptures the platelets clump together at the siteof damage and can block the vessel, which can cause a heart attack.

Controls stickiness

Lead researcher Professor Alastair Poole said: "We havediscovered that a protein called PKC alpha is a major controller ofplatelet stickiness - if you remove PKC alpha the dangerous blood clotsdon't form.

Platelets reach out sticky arms to each other to form clots "Equally important, and surprising, is that we have alsofound that absence of PKC alpha doesn't seem to impair the normalcontrol of bleeding, unlike some current anti-clotting medicines.

"It is too early to put anti-PKC alpha drugs on the market but weare excited to have made a step in the right direction towards thedevelopment of a new family of potentially useful anti-clottingmedicines for heart patients."

Professor Jeremy Pearson is associate medical director at the British Heart Foundation, which funded the research.

He said: "We do have some effective clot-busting andclot-preventing medicines at present, but they can be rather bluntinstruments with serious side-effects such as increased bleeding.