Viagra as a Heart Pill

The erection drug Viagra (more commonly known as “Vitamin V”, “The Blue Pill”, or “Blue Diamond”) was originally designed as a medication for treating high blood pressure and angina (a chest pain due to ischemia). The results of the studies carried out back then indicated that Viagra was not successful in treating angina. However, it did give rise to penile erections. After gaining popularity as an erection drug, it just so happens that recently, Viagra has been found to have the ability to “soften” or relax the muscles of the heart.

The active ingredient in Viagra, sildenafil, has been found to alleviate heart problems. Scientists at Ruhr Universitat Bochum in Germany found that Viagra activates an enzyme that forms the protein titin in the muscle cells of the heart and causes it to relax.

The mechanism is as follows; sildenafil inhibits a specific enzyme (phosphodiesterase 5 A), causing the increased formation of the messenger substance cGMP. This activates the enzyme protein kinase G, which indirectly causes the cardiac walls in the heart to relax.

“The titin molecules are similar to rubber bands” explains the Bochum physiologist. “They contribute decisively to the stiffness of the cardiac walls.”

The team of scientists developed their theory by studying dogs with diastolic heart failure. Diastole is a phase of the cardiac cycle in which the ventricles of the heart are relaxed and are filling up with incoming blood from the body through the inferior vena cava, the pulmonary veins and the superior vena cava. Hence, diastolic heart failure refers to the decline in hearts ability to carry out this process; when the ventricles do not efficiently fill up with blood. Based on the study they carried out, the scientists at Bochum showed that sildenafil makes stiffened cardiac walls more elastic.

“We have developed a therapy in an animal model that, for the first time, also raises hopes for the successful treatment of patients.” says Prof. Wolfgang Linke of the RUB Institute of Physiology.

“Of all the patients aged over 60 who are in hospital because of a weak heart, half suffer from diastolic heart failure” explains Linke. “Although we know that the decreased distensibility (i.e. lack of swelling/growth) of the cardiac walls is the cause, the disease cannot be treated properly with today’s medicines.”

The efficacy of sildenafil in people is already being tested.

“If, for the first time, the drug is found to have a positive effect on heart failure, we would already have a molecular mechanism on hand to explain the effect,” says Linke.

The study has been published in the journal Circulation. It is hopeful that the erection pill Viagra may soon be “Viagra for the Heart” and help battle heart diseases.

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About the author

Tara Sud

After living the first seventeen years of my life in India, I travelled to the England to study at the University of York. My undergraduate degree was in English Literature and Linguistics, and I am currently completing my Masters degree in Romantic and Sentimental Literature. Apart from writing, I thoroughly enjoy playing piano and consider myself a commendable Scrabble competitor. I have a keen interest in literature, psychology and biology and love to learn in general.