Erectile disfunction affects more that 150 million males worldwide and results from a number of different conditions. Treatments such as Viagra, Levitra, or Cialis work by delaying the degradation of the messenger 3’5′-cyclic guanosine monophosphate (cGMP) and prolonging the length of the erection. However, these treatments cannot be used by patients with certain pre-existing medical conditions.
Martin Fussenegger and co-workers, ETH Zurich, Switzerland, and Institute Universitaire de Technologie, Villeurbanne, France, realized that a synthetic device that can trigger an erection on demand would be a novel addition to the treatments available for erectile dysfunction. The researchers devised an erectile optogenetic stimulator (EROS) that comprises a synthetic designer guanylate cyclase. In the presence of blue light from a commercially available lamp, a surge of cGMP that leads to an erection is produced.
Rats treated with EROS showed a range of penile responses in the presence of light, from erection to ejaculation, whereas no response was observed from untreated rats. In further experiments, it was shown that the rats could be repeatedly stimulated by illumination, and that longer erection times were observed upon illumination when the rats were treated with EROS and sildenafil (Viagra). This strategy is complementary to established treatments, as it results in a triggerable erection, rather than delaying the degradation of cGMP.
- A Synthetic Erectile Optogenetic Stimulator Enabling Blue-Light-Inducible Penile Erection,
Taeuk Kim, Marc Folcher, Marie Doaud-El Baba, Martin Fussenegger,
Angew. Chem. Int. Ed. 2015.