Testosterone Might Cause Relaxation of Human Corpus Cavernosum by Potassium Channel Opening Action


YILDIZ O., Seyrek M., Irkilata H. C., Yildirim I., Tahmaz L., Dayanc M.

Urology, cilt.74, sa.1, ss.229-232, 2009 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 74 Sayı: 1
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.urology.2008.12.022
  • Dergi Adı: Urology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.229-232
  • Sağlık Bilimleri Üniversitesi Adresli: Evet

Özet

Objectives: To investigate the effect of testosterone on contractile tone of endothelium-denuded human corpus cavernosum strips. Human studies designed to examine a possible relaxant effect of testosterone on corpus cavernosal circulation are lacking. Methods: Testosterone (0.1-300 μM) was added cumulatively to organ baths after precontraction of isolated human corpus cavernosum strips (n = 5) with KCl (45 mM). Testosterone-induced responses were tested in the presence of nonselective, large, conductance Ca2+-activated and voltage-sensitive K+ channel inhibitor tetraethylammonium (1 mM), adenosine triphosphate-sensitive K+ channel inhibitor glibenclamide (10 μM), voltage-dependent inward rectifier K+ channel inhibitor barium chloride (30 μM) and voltage-sensitive K+ channel inhibitor 4-aminopyridine (1 mM). Results: Testosterone (0.1-300 μM) produced relaxation in human corpus cavernosum (maximum relaxation 65.4% ± 3.3% of KCl-induced contraction) that reached a maximum at a concentration of 300 μM. Testosterone-induced relaxation was significantly attenuated by glibenclamide, but it was not affected by the other K+ channel inhibitors (tetraethylammonium, barium chloride, or 4-aminopyridine). Conclusions: Testosterone might induce relaxation in human isolated corpora cavernosa strips by activation of smooth muscle adenosine triphosphate-sensitive K+ channels. This finding suggests that testosterone, in addition to its known endothelial action, might regulate erectile function locally by its action on the smooth muscle of the human corpus cavernosum. © 2009 Elsevier Inc. All rights reserved.