Localization of NADPH diaphorase and vasoactive intestinal polypeptide-containing neurons in the efferent pathway to the rat corpus cavernosum

Eur Urol. 1997;32(1):100-4.


Objective: We examined the coexistence of nitric oxide synthase (NOS) and vasoactive intestinal peptide (VIP) in the efferent pathway to the rat corpus cavernosum.

Methods: We used NADPH diaphorase (ND) histochemical staining, a specific marker of neuronal NOS, in combination with retrograde axonal transport of True Blue (TB) and VIP immunohistochemistry.

Results: Many neurons were labeled by TB in the cavernous nerve and the body of the major pelvic ganglion (MPG), and fewer neurons in the pelvic nerve. In the cavernous nerve, about 90% of TB-labeled efferent neurons were ND positive, and about 80% in the body of the MPG and pelvic nerve. Besides, 60-80% of TB-labeled efferent neurons projecting to the corpus cavernosum showed VIP immunoreactivity. VIP was colocalized with NOS in 70-80% of neurons.

Conclusions: These findings suggest that most of the ND-positive nerves and terminals in the corpus cavernosum come from the MPG via the cavernous nerve and that NO plays an important role; it may act in combination with NO because most NOS-containing neurons simultaneously showed VIP immunoreactivity.

MeSH terms

  • Animals
  • Fluorescent Dyes
  • Frozen Sections
  • Immunohistochemistry
  • Male
  • NADPH Dehydrogenase / metabolism*
  • Neurons, Efferent / enzymology*
  • Neurons, Efferent / metabolism
  • Nitric Oxide Synthase / metabolism*
  • Penis / innervation*
  • Rats
  • Rats, Sprague-Dawley
  • Vasoactive Intestinal Peptide / metabolism*


  • Fluorescent Dyes
  • Vasoactive Intestinal Peptide
  • Nitric Oxide Synthase
  • NADPH Dehydrogenase