title: Erectile function in two-kidney, one-clip hypertensive rats is maintained by a potential increase in nitric oxide production.
abstract: BACKGROUND
  Hypertension is closely associated with erectile dysfunction (ED) as it has been observed in many experimental models of hypertension. Additionally, epidemiological studies show that approximately a third of hypertensive patients have ED.
  
  
  OBJECTIVE
  To test the hypothesis that the two-kidney, one-clip (2K-1C) rat model of hypertension displays normal erectile function due to increased nitric oxide (NO) production in the penis.
  
  
  METHODS
  Ganglionic-induced increase in intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio was used as an index of erectile function in 2K-1C and in normotensive sham-operated (SHAM) anesthetized rats. Cavernosal strips from hypertensive and normotensive rats were used for isometric tension measurement. The contraction induced by alpha-adrenergic agonist phenylephrine and the relaxation induced by the NO donor sodium nitroprusside (SNP) and by the Rho-kinase inhibitor Y-27632 were performed in the absence and in the presence of the NO synthase inhibitor N(omega)-nitro-L-arginine (L-NNA).
  
  
  RESULTS
  Changes in ICP/MAP induced by ganglionic stimulation were not different between 2K-1C and SHAM rats. The contractile response induced by phenylephrine as well as the relaxation induced by SNP or the Y-27632 were similar in cavernosal strips from both groups. However, in the presence of L-NNA, the relaxation induced by Y-27632 was significantly impaired in 2K-1C compared to SHAM.
  
  
  CONCLUSIONS
  These data suggest that hypertension and ED could be dissociated from high levels of blood pressure in some animal models of hypertension. Erectile function in 2K-1C hypertensive rats is maintained in spite of the increased Rho-kinase activity by increased NO signaling.
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA.
authors.forename: A Elizabeth
authors.initials: AE
authors.lastname: Linder
authors.forename: Anne M
authors.initials: AM
authors.lastname: Dorrance
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Mills
authors.forename: R Clinton
authors.initials: RC
authors.lastname: Webb
authors.forename: Romulo
authors.initials: R
authors.lastname: Leite
mesh_terms: D000577:Amides / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D007172:Erectile Dysfunction / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology; D045888:Ganglion Cysts / Q000378:metabolism; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology; D007213:Indomethacin / Q000494:pharmacology / Q000627:therapeutic use; D007668:Kidney / Q000502:physiology*; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology / Q000627:therapeutic use; D010413:Penis / Q000187:drug effects / Q000378:metabolism*; D010656:Phenylephrine / Q000494:pharmacology / Q000627:therapeutic use; D011312:Pressure; D011725:Pyridines / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors
chemical_list: D000577:Amides; D000959:Antihypertensive Agents; D011725:Pyridines; C108830:Y 27632; D009599:Nitroprusside; D010656:Phenylephrine; D009569:Nitric Oxide; D054460:rho-Associated Kinases; D007213:Indomethacin