The density and distribution of endothelin 1 and endothelin receptor subtypes in normal and diabetic rat corpus cavernosum

Br J Urol. 1995 Aug;76(2):203-7. doi: 10.1111/j.1464-410x.1995.tb07675.x.

Abstract

Objective: To investigate the density and distribution of endothelin 1(ET-1) and endothelin receptor subtypes in rat cavernosal tissue, and to assess any changes brought about by the onset of diabetes mellitus (DM).

Materials and methods: Hyperglycaemic non-ketotic diabetes mellitus was induced in five rats using streptozotocin (STZ). Two months later the penises were excised and stored at -70 degrees C. Longitudinal serial sections (6 microns) were cut using a cryostat and thaw- mounted onto gelatinized microscope slides. Low and high resolution autoradiographs were taken using radioligands for ET-1 and endothelin A (ETA) and endothelin B (ETB) receptors and the autoradiographs analysed densitometrically. These results were compared with those from five age-matched control rats.

Results: ET-1 and ETA receptor binding was primarily localized to the endothelium lining the cavernosal lacunar spaces: trabecular corporeal smooth muscle was much less intensely stained. No ETB receptor binding could be demonstrated, but increased binding of ET-1 and ETA receptors was seen in the diabetic cavernosal tissue.

Conclusion: ET-1 and ETA receptor binding is increased in diabetic rat cavernosal tissue. A reduction in receptor linked nitric oxide (NO) release has previously been reported in diabetic rats. This finding may provide an explanation for the upregulation of ET-1 and ETA receptor binding in the diabetic rat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoradiography
  • Diabetes Mellitus, Experimental / metabolism*
  • Endothelins / metabolism*
  • Male
  • Penis / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Endothelin / metabolism*

Substances

  • Endothelins
  • Receptors, Endothelin