NITRIC-OXIDE SYNTHASE - A NEW DIAGNOSTIC-TOOL FOR NEUROGENIC IMPOTENCE

Cavernosal biopsy specimens obtained from men undergoing penile surger y permitted determination of the diagnostic value of nitric oxide synt hase in neurogenic impotence. In biopsy specimens obtained from 25 men , the presence of nitric oxide synthase (NOS), as shown by nicotinamid e adenine dinucleotide phosphate (NADPH) diaphorase staining, was dete rmined in nerve fibers, smooth muscle, and sinusoidal endothelium. Pos itive staining for NOS correlated significantly (p less-than-or-equal- to 0.001) with a clinical history of cavernous nerve integrity. In com parison, staining with protein gene product (PGP 9.5), an excellent ge neral nerve stain, lacked any degree of specificity as an indicator of nerve status. NADPH diaphorase may provide important insight into the cavernous nerve integrity of the patient. This report is the first to describe histologic features of human cavernosal tissue biopsies that will allow the direct diagnosis of neurogenic impotence owing to cave rnous nerve damage.