Viagra, a drug used for erectile dysfunction and one of the most frequently prescribed medications in the United States, has been found to reduce the effects of stroke in laboratory animals, according to a Henry Ford Hospital study. The research will be presented Friday at the 27th International Stroke Conference in San Antonio, Texas.
"What we found is that we can use certain drugs like Viagra to create new brain cells," said Michael Chopp, Ph.D., scientific director of the Neuroscience Institute at Henry Ford Hospital. "And these cells are created in both elderly as well as young subjects.
"When animals with stroke are treated with Viagra, the drug provides very significant neurological functional benefit. These animals do much better on many different outcome measures, including motor function, somatosensory testing, neurological outcome and weight gain. There are far fewer functional deficits.
We can treat with Viagra days after stroke and there is a significant reduction in neurological deficit and a significant induction of new brain cells," said Chopp.
Viagra was given to rats for six days after induced stroke. After 28 days, there were significantly more new brain cells in the rats treated with Viagra. In addition, the rats were also tested for sensory, motor and agility to measure brain impairment by checking the speed in which they removed adhesive from their feet and their ability to walk on a grated pathway. Those treated with Viagra performed better.
Viagra or sildenafil citrate was selected as the drug to test because it is similar chemically to other compounds shown to improve function in animals after stroke. Chopp believes that Viagra activates a molecule called Cyclic GMP in brain tissue and that it is Cyclic GMP that creates new brain cells.
The next step is further testing to find the therapeutic window and to test for adverse effects in rats before considering human trials, said Chopp.
The Viagra research by Chopp and his team is a continuation of their research to find compounds that generate new brain cells in animals and improve function after neural injury and stroke.
"We essentially focused on the development of therapies to restore function in neurological disease and neuro-injury. We demonstrated with great success in the animal models that that we can restore function with cellular therapies and with bone marrow cells and cord blood," Chopp said.
"Now we have a pharmaceutical therapy that can greatly enhance restoration after neural injury and possibly after neuro-degenerative disease. This creates great opportunity to find new treatments for these types of disease processes in humans."
