Europe South Asia Asia Pacific Americas Middle East Africa BBC Homepage World Service Education



Front Page

World

UK

UK Politics

Business

Sci/Tech

Health

Education

Sport

Entertainment

Talking Point
On Air
Feedback
Low Graphics
Help

Monday, August 3, 1998 Published at 20:25 GMT 21:25 UK


Health

Scientists crack cocaine secret

Cocaine stimulates the cells to send out the wrong messages

Scientists have discovered how cocaine causes heart attacks and may be able to use the knowledge to develop an effective treatment.

Writing in the academic journal Circulation, German scientists say cocaine attacks the endothelium, a layer of cells that lines the inside of blood vessels.

Cocaine stimulates receptors in the cells to release large quantities of endothelin, a chemical that causes blood vessels to contract.

Excessive amounts of the chemical can make blood vessels constrict faster and tighter, thereby choking off blood supply to the heart.

Important discovery


[ image: Discovery may help treatment of overdoses]
Discovery may help treatment of overdoses
Lead researcher Dr Rainer Arendt said: "This finding opens the opportunity to develop powerful drugs to fight against cocaine's effects.

"Not only will this provide help in the occasionally difficult medical therapy of treating cocaine-induced heart attack or stroke, but it may prove to be important in understanding stress-related heart attacks and cardiac arrests.

"Cocaine seems to use the same pathways that are activated in the body's response to stress."

Blocking the effect

After identifying cocaine's effects on blood vessels, the researchers turned their attention to ways to block these effects.

By using two drugs that readily interact with cell receptors, the scientists stopped the cocaine-induced release of endothelin from cells.

Used in healthy cells unaffected by cocaine, the drugs haloperidol and ditolylguanidine did not show significant effects on reducing the release of endothelin.

But using haloperidol alone eliminated all effects of cocaine on endothelin release.

Ditolylguandine also was shown to significantly reduce the increased release of endothelin that is associated with cocaine.

Other factors

Dr Arendt and his colleagues examined blood and urine samples of 12 cocaine-intoxicated people and 13 healthy non-users.

The endothelin levels in blood and urine were 3 to 3.5 times higher in people who had used cocaine when compared to the individuals who had not.

However Dr Arendt said other factors may be partially responsible for cocaine-related cardiovascular disease.

"All of the cocaine-intoxicated patients in our study had elevated endothelin levels, but they did not all have a heart attack or stroke," he says.

"That means other factors come into play. It is likely that the interaction between endothelin and other constricting chemicals causes prolonged constricting of the blood vessels in the heart and brain."



Advanced options | Search tips




Back to top | BBC News Home | BBC Homepage | ©


Health Contents

Background Briefings
Medical notes
Relevant Stories

30 Jul 98 | Health
Paracetamol may combat heart disease

09 Jun 98 | Latest News
Scientists set blood pressure target

26 May 98 | Latest News
Heart device could clear blood clots





Internet Links

British Heart Foundation

American Heart Association


The BBC is not responsible for the content of external internet sites.




In this section

Disability in depth

Spotlight: Bristol inquiry

Antibiotics: A fading wonder

Mental health: An overview

Alternative medicine: A growth industry

The meningitis files

Long-term care: A special report

Aids up close

From cradle to grave

NHS reforms: A guide

NHS Performance 1999

From Special Report
NHS in crisis: Special report

British Medical Association conference '99

Royal College of Nursing conference '99