Autoradiographic localization of nitric oxide synthase binding sites in normal and diabetic rat corpus cavernosum

Eur Urol. 1996;30(4):506-11. doi: 10.1159/000474225.


Objectives: To investigate density and distribution of nitric oxide synthase (NOS) binding sites in rat cavernosal tissue, and to assess any changes brought about by the onset of diabetes mellitus.

Methods: Hyperglycaemic non-ketonuric diabetes mellitus was induced in 5 rats using streptozotocin. The penises were excised from these rats 2 months after the administration of streptozotocin and stored at -70 degrees C. Longitudinal serial sections (6 microns) were cut in a cryostat and thaw mounted onto gelantinized microscope slides. Low- and high-resolution autoradiography was performed using a radioligand for NOS. Densitometric analysis was performed on the autoradiographs and the results compared with those obtained from 5 age-matched no-diabetic rats.

Results: NOS binding was primarily localized to the endothelium lining the cavernosal lacunar spaces. Significantly increased binding of NOS was seen in the diabetic cavernosal tissue 2 months after induction of diabetes mellitus.

Conclusions: NOS binding is present on the endothelium of the rat corpus cavernosum and is increased in diabetic rats 2 months after streptozotocin administration. This increase in NOS binding may be part of the endothelial dysfunction which is reported in the corpus cavernosum of diabetic patients or rats.

MeSH terms

  • Animals
  • Autoradiography
  • Binding Sites
  • Diabetes Mellitus, Experimental / enzymology*
  • Male
  • Nitric Oxide Synthase / metabolism*
  • Penis / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Urethra / metabolism


  • Nitric Oxide Synthase