14 DAY TRIAL // Urinating countless times a day is one thing, but what follows after surgery is much worse: impotence. Operation of prostate cancer is in most cases connected to damage to the cavernous nerve, which means blood vessels necessary to induce an erection are blocked. Even nerve-sparing surgeries involve a long time recovery from radical prostatectomy. 15 to 30 million Americans experience impotence, and many cases are due to nerve damage.
Now gene therapy developed by a team at the University of Pittsburgh School of Medicine could make a man recover his complete health in just four weeks by stimulating two nerve growth factors. The research team introduced either the gene for the glial cell line derived neurotrophic factor (GDNF) or the GDNF family ligand (neurturin) into a carrier herpes simplex virus (HSV). The recombinant viruses were injected into the cavernous nerve of rats.
GDNF boosts nerve growth, involved in the feeding and regrowth of penile nerves, whole neurturin is a chemical closely related to GDNF. Control rodents were injected with just the virus without the two genes inserted. Four weeks later, the individuals that received HSV-GDNF displayed a surprising recovery of the intracavernous pressure (ICP) and systemic arterial pressure (AP) compared to control impotent rodents, which received just the simple virus or nothing at all. Individuals receiving just HSV-neurturin also presented high recovery of ICP and AP compared to control rodents four weeks later. The researchers could check if the genes were inserted into the right nerve cells through fluorescent protein techniques.
"HSV delivery of GDNF or neurturin presents a potentially important new approach for the treatment of ED. Because the herpes virus persists in the nerve cell for as long as it is alive and nerve cells typically do not reproduce, this represents the first-ever demonstration of a long-term treatment for ED that does not rely on the chronic administration of drugs that can have potentially harmful side effects," said lead researcher Dr. Joseph C. Glorioso, chair of the department of biochemistry and molecular genetics.