ORLANDO - May 25, 2002 - A single injection of naked human maxi-K gene into penile smooth muscle chronically reversed the effects of aging for up to six months in a rat model and may be successful in the long-term treatment of age-related erectile dysfunction, according to new research from the Albert Einstein College of Medicine in New York. Arnold Melman, M.D. will present the study during an unmoderated poster session on Tuesday, May 28.
Researchers used 191 rats in the study, which were given either phosphate buffered saline, 1000 ng vector or 10, 100 or 1,000 ng of nSlo/pcDNA using intercavernosal injection. The rats were examined in terminal experiments at monthly intervals from one to six months following injection. Researchers measured intracorporeal pressure in response to nerve stimulation to measure the effect of the therapy.
Data collected showed a significant effect of treatment on erection that correlated with the increased dosage of the gene. In the rats receiving the 100 ng and 1,000 ng. dose, results were sustained for up to six months after a single injection. Researchers also noted that organ systems were not affected by the treatment. The therapy may give physicians a new alternative to treat age-related erectile dysfunction in the future.
Current pharmacological treatments involve the nitric oxide pathway in the muscle, and sustain relaxation. Muscle tone does not decrease, and the effects of aging are not inhibited.
This mode of gene therapy would, in essence, reverse the effect of aging. Membrane-bound potassium channels both initiate and maintain smooth-muscle relaxation, and the injection of the hSlo/Maxi-K gene gives the muscle an extra potassium channel, and allows for a "super-physiologic" response to what is naturally happening, according to Melman.
"The beauty of [injection of Maxi-K] is that the effect only occurs when the body gives the natural signal," he said.
Additional resources on erectile dysfunction are available from MayoClinic.com:
http://www.mayoclinic.com/health/erectile-dysfunction/DS00162
