October 19, 2010

Heart Symptoms In MD May Be Helped With Viagra

Viagra, the famous little blue pill that millions of men use for erectile dysfunction, and originally developed to help ailing hearts, may now also help treat heart symptoms of muscular dystrophy, according to researchers Monday.

Mice that were genetically engineered to have a condition similar to Duchenne muscular dystrophy were tested and scientists found the drug could improve how the heart works, according to their research.

Joseph Beavoa of the University of Washington and colleagues at the University of North Carolina said it was not clear yet just how the drug helps mice, but they said it may be worth trying it as a treatment for muscular dystrophy.

Duchenne muscular dystrophy affects roughly 1 in 3,500 males, according to the National Institutes of Health.

"Duchenne muscular dystrophy (DMD) is a progressive and fatal genetic disorder of muscle degeneration. Patients with DMD lack expression of the protein dystrophin as a result of mutations in the X-linked dystrophin gene," Beavoa and colleagues noted.

Because boys only carry one X chromosome, they are much more likely to be affected than girls, who have two copies of the X chromosome and, thus, are likely to have one healthy copy of the gene.

As a person with muscular dystrophy grows up, the muscles all throughout the body break down, including the heart. Many patients die of heart failure and most with the condition die before age 40.

Pharmaceutical company Pfizer produces and sells Viagra, generically known as sildenafil, for erectile dysfunction, but also markets it under the name Revatio to treat a heart condition called pulmonary hypertension. It is considered a PDE5 inhibitor that works by increasing blood flow.

Working with funds from the National Institutes of Health, the team tested Viagra in mice with heart damage similar to that seen in muscular dystrophy. They found it slowed the damage and, in some cases, even reversed it. 

"Although PDE5 inhibitors will certainly not cure DMD, the current studies suggest that they could be used in combination with current or future therapies," the researchers, reporting in the Proceedings of the National Academy of Sciences, wrote.  ã


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