Researchers identify key step in cocaine-induced heart enlargement, sudden death

Sep 07, 2006

Cocaine, in concentrations commonly sold on the street, causes the abnormal buildup of primitive proteins in heart muscle – a process causing heart enlargement that can ultimately lead to sudden death, report researchers at the University of South Florida College of Medicine and James A. Haley Veterans' Hospital.

The study was published in the July 2006 issue of the Journal of Cardiovascular Pharmacology.

"This finding is important because cocaine-related deaths most commonly occur in young people between the ages of 18 and 29, many of whom are totally unaware of the drug's toxic effects," said Robert Henning, MD, professor of medicine at the USF College of Medicine at the Haley VA Hospital.

Using heart muscle cells from adult rats, Dr. Henning and his colleagues found that cocaine activates the enzyme calmodulin kinase II (CaMK), which increases calcium within the heart muscle cells. The increase in calcium appears to be a key step in prompting the accumulation of primitive fetal proteins not normally found in adult heart muscle cells – a process that causes the muscles cells, and eventually the heart, to enlarge. It also triggers irregular heart rhythms that can cause sudden death.

The researchers also demonstrated that the CaMK inhibitors Nifedipine and KN-62 appear to limit the accumulation of abnormal proteins in heart muscle, suggesting they may be a useful therapy for cardiac hypertrophy, or enlarged heart.

The USF researchers' findings may also have wider implications for other forms of heart enlargement caused by chronic disease. "The biomolecular pathway that we've identified likely also plays an important role in heart hypertrophy due to hypertension, heart attacks and heart failure," Dr. Henning said.

In cardiac hypertrophy, or enlarged heart, the heart's main pumping chamber becomes abnormally large as a result of an increased workload. In time, fibers of the heart muscle thicken and become less able to relax, reducing the heart's capacity to meet the body's demands for normal blood circulation.

Approximately 5 million Americans use cocaine on a regular basis. Cardiac hypertrophy may affect as many as 47 percent of chronic cocaine users with normal blood pressure, Dr. Henning said.

Source: University of South Florida Health

Explore further: Better classification to improve treatments for breast cancer

add to favorites email to friend print save as pdf

Related Stories

Hitchhiking robot reaches journey's end in Canada

31 minutes ago

A chatty robot with an LED-lit smiley face sent hitchhiking across Canada this summer as part of a social experiment reached its final destination Thursday after several thousand kilometers on the road.

Microsoft to unveil new Windows software

46 minutes ago

A news report out Thursday indicated that Microsoft is poised to give the world a glimpse at a new-generation computer operating system that will succeed Windows 8.

Ecologists team up to buy Texas bayside ranch

48 minutes ago

The Texas Parks and Wildlife Foundation and partners have announced the purchase of a sprawling southeast Texas ranch with funds put aside after the BP oil spill.

Climate change: meteorologists preparing for the worst

58 minutes ago

Intense aerial turbulence, ice storms and scorching heatwaves, huge ocean waves—the world's climate experts forecast apocalyptic weather over the coming decades at a conference in Montreal that ended Thursday.

Recommended for you

Better classification to improve treatments for breast cancer

1 hour ago

Breast cancer can be classified into ten different subtypes, and scientists have developed a tool to identify which is which. The research, published in the journal Genome Biology, could improve treatments and targeting of tre ...

Oral contraceptive equal to antibiotics for acne care

3 hours ago

(HealthDay)—At six months, oral contraceptive pills (OCPs) are comparable to systemic antibiotics for acne management, according to a review published in the September issue of the Journal of the American Ac ...

Pay-for-performance not found to impact access to CABG

3 hours ago

(HealthDay)—For patients with acute myocardial infarction (AMI), treatment at pay-for-performance (P4P) hospitals is not associated with a change in the rate of coronary artery bypass graft (CABG) surgery, ...

Risk of diabetes up in hodgkin's lymphoma survivors

3 hours ago

(HealthDay)—Para-aortic radiation correlates with increased diabetes mellitus (DM) risk for Hodgkin's lymphoma (HL) survivors, according to a study published online Aug. 25 in the Journal of Clinical On ...

User comments : 0