title: Erectile dysfunction in heart failure rats is associated with increased neurogenic contractions in cavernous tissue and internal pudendal artery.
abstract: OBJECTIVE
  The rates of erectile dysfunction (ED) in heart failure (HF) are extremely high. This study tested the hypothesis that rats with HF display ED and that HF leads to increased sympathetic-mediated contractile tone of the cavernous tissue and/or internal pudendal arteries (IPA) as potential mechanisms contributing to ED.
  
  
  METHODS
  HF was induced in Wistar rats by ligation of the left anterior descending coronary artery. Changes in the ratio of intracavernosal pressure/mean arterial pressure (ICP/MAP) after electrical stimulation of major pelvic ganglion were determined in vivo. Cavernosal and IPA contractions were induced by electric field stimulation (EFS) and phenylephrine. RhoA, Rho kinase 2 (ROCK 2) and myosin phosphatase target protein 1 (MYPT-1) protein expression and phosphorylation levels were also determined.
  
  
  RESULTS
  HF rats display impaired erectile function represented by decreased ICP/MAP responses. EFS-mediated contractions were increased by HF in cavernous tissue and IPA. Contractions induced by phenylephrine were increased in cavernous tissue of HF rats, but decreased in IPA rings. Moreover, HF decreased RhoA protein expression, but increased ROCK 2 and MYPT-1 phosphorylation levels in cavernous tissue. In conclusion, rats with HF induced by myocardial infarction display ED in vivo and increased sympathetic-mediated contractile responses in cavernous tissue and IPA. Increased sympathetic-mediated contractile responses were associated with increased ROCK 2 and MYPT-1 phosphorylation in cavernosal tissue, suggesting the involvement of ROCK signaling pathway in ED genesis.
  
  
  CONCLUSIONS
  Our findings suggest new mechanisms linking HF to ED, providing potential therapeutic targets for treating ED associated to HF.
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Fernanda Luciano
authors.initials: FL
authors.lastname: Rodrigues
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Rhéure Alves M
authors.initials: RA
authors.lastname: Lopes
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Rafael Sobrano
authors.initials: RS
authors.lastname: Fais
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: de Oliveira
authors.affiliation: Department of Pathology and Legal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Cibele M
authors.initials: CM
authors.lastname: Prado
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Rita C
authors.initials: RC
authors.lastname: Tostes
authors.affiliation: Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil. Electronic address: fcarneirousp@yahoo.com.br.
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Carneiro
mesh_terms: D000818:Animals; D062186:Arterial Pressure; D001158:Arteries / Q000503:physiopathology*; D007172:Erectile Dysfunction / Q000150:complications* / Q000503:physiopathology*; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology*; D008297:Male; D010413:Penis / Q000098:blood supply* / Q000503:physiopathology; D017208:Rats, Wistar; D015398:Signal Transduction; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D020742:rhoA GTP-Binding Protein
keywords: Corpora cavernosa; Erectile dysfunction; Heart failure; RhoA/Rho kinase pathway