A study has suggested that compounds found in the erectile dysfunction medication Viagra may work to combat heart disease by shrinking abnormally large hearts.
The drug is already in clinical trials investigating whether it can prevent heart disease, but the research, published online in the journal Circulation Research. Abnormal muscle growth in the heart is known as hypertrophy and is caused by a diseased heart having to work harder to push around blood, causing the overworked heart muscles to grow. This itself can cause the chamber walls of the heart to thicken, slow down heartbeats and cause potentially fatal arthymias.
The scientists on the study said that Viagra interferes with enzymes, known as PDEs, that break down the molecule cyclic guanosine monophosphate, or cGMP, that normally would stop the cells in the heart muscle growing. This means that the drug works to control hypertrophy. They also discovered that a specific PDE, PDE1a, also breaks down cGMP, using a different mechanism to Viagra.
Chen Yan of the Medical Centre at the University of Rochester and one of the study’s authors, said that based on the results of the trials they would be investigating ways to develop new medications to control abnormal heart growth. He added that it was not yet clear whether combining PDE1 inhibitors with Viagra would be effective at combating heart disease but said that further tests on animals were now scheduled.