Could a blue light treat erectile dysfunction? Radical therapy may replace Viagra, say scientists

• A gene construct that reacts to blue light is injected into the penis
• Calcium levels in the cells drop, which in turn relaxes muscle cells
• This increases blood flow to tissue, triggering 'on demand' erections
• Treatment is successful in mice, but has yet to be tested on humans 

Instead of reaching for a 'blue pill', men suffering from erectile dysfunction should be exposing themselves to blue light.

This is according to a Swiss scientists who are developing a Viagra-replacement therapy that involves injecting the penis with artificial DNA.

When the treated tissue is exposed to blue light, the gene construct increases blood flow to cause an erection without any sexual stimulation.

Instead of reaching for a 'blue pill', men suffering from erectile dysfunction should be exposing themselves to blue light. This is according to a Swiss scientists who are developing a Viagra-replacement therapy that involves injecting the penis with artificial DNA

Scientists say this gives the treatment an advantage over Viagra which only helps to prolong an erection rather than trigger it.

ETH Zürich researchers, led by Professor Martin Fussenegger, explained that as soon as the tissue is exposed to the light, a precursor molecule, known as guanosine triphosphate or GTP, is converted into the second messenger, known as cGMP.

This allows calcium channels to close, reducing calcium levels in the cells, which in turn relaxes muscle cells and increases blood flow to the erectile tissue.

The penis becomes stiff, and an enzyme begins slowly breaking down cGMP so that the erection wears off with time.

When the treated tissue is exposed to blue light, the gene construct increases blood flow to cause an erection without any sexual stimulation. Scientists say this gives the treatment an advantage over Viagra which only helps to prolong an erection rather than trigger it

The 'blue pill' blocks this enzyme and intensifies and prolongs the erection, but it cannot trigger one.

'In this way, we circumvent the usual sexual stimulation that triggers a cascade of signals in the body and ultimately leads to an erection,' says Fussenegger.

The researchers tested their new development in male rats by injecting the gene construct into the erectile tissue - with good results.

In most cases, the blue light acted like a switch that allowed the rats' erection to be 'turned on'. For some of the animals, the stimulation even led to ejaculation.

'The system of an erection is very similar across all mammals,' says Fussenegger. He is therefore convinced that the gene construct will also work in humans.

Apparently, it appeared very early in evolutionary history and has been preserved. 'Even Viagra works on rats. It prolongs the erection's intensity, just as it does in humans.'

The ETH professor does not anticipate many side-effects from this type of gene therapy.

Professor Fussenegger says that an injecting the penis is relatively pain-free.

'Injection of a gene construct should not be a barrier to potential users, as injections in the erectile tissue are already a standard treatment for erectile dysfunction these days,' says Fussenegger.

The erectile tissue is largely insensitive to pain; it is also for the most part detached from normal blood circulation, so the probability that the gene construct could reach other parts of the body is very low.

ETH researchers in Basel have worked on this gene construct for four years and for the time being it exists only as a prototype. Tests in humans have yet to be conducted.

From the age of 30, scientists claim the number of men who have erectile problems increases. In the over-60 age group, more than half of all men have been affected by erectile dysfunction.

The main causes include cardiovascular disease, diabetes, hormonal imbalance, neurological disease and the side-effects of medication.

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