Rare NO synthase jumpstarts erections

The relatively rare, alternatively spliced beta form of neuronal nitric oxide synthase can trigger penile erections in mice lacking the primary form, underscoring the essential role of nitric oxide in reproduction, according to a new study in the Proceedings of the National Academy of Sciences.This research "really puts the final stamp on the whole issue that NO is the final mediator," study author Arthur Burnett told The Scientist.Fourteen years ago, Burnett and his colleagues at the James Buchanan Brady Urological Institute of Johns Hopkins first implicated the gaseous messenger molecule nitric oxide as the primary mediator of penile erection. In subsequent work with mice, they found that neuronal NO synthase (nNOS) is required to initiate the response, while endothelial NOS (eNOS) sustains maximal erection.Consequently, he and other researchers were surprised to find that mutant mice knocked out for eNOS, the predominant form of nNOS, or both, still had...