Reverse Viagra

http://www.newscientist.com/channel/health/dn13461-relief-in-sight-for-sufferers-of-constant-erections.html

Impotence is bad enough, but sufferers of the opposite problem – priapism – might consider themselves even more unfortunate.The condition – constant, painful erections in the absence of arousal – is embarrassing and potentially dangerous. In the worst cases it can lead to permanent erectile dysfunction or even gangrene.Now relief is at hand – researchers at the University of Texas Medical School at Houston say they have figured out the biochemical basis of the disorder.Raised levels of the biochemical adenosine – which can cause blood vessels to dilate and has the potential to influence blood flow into the penis – seem to be the cause, says team leader Yang Xia.To test the idea, the team used mice genetically altered to be deficient in an enzyme that breaks down adenosine. As a result the animals have very high adenosine levels.