title: Chronic ethanol consumption induces cavernosal smooth muscle dysfunction in rats.
abstract: OBJECTIVE
  To investigate the effects of chronic ethanol consumption on nitric oxide (NO)-mediated relaxation in rat cavernosal smooth muscle (CSM).
  
  
  METHODS
  Male wistar rats were divided into 2 groups: control and ethanol. CSM obtained from both groups were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hertz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (0.01-1000 micromol L(-1)), sodium nitroprusside (SNP, 0.01-1000 micromol L(-1)), or EFS (1-32 Hz) in strips precontracted with phenylephrine (10 micromol L(-1)). Blood ethanol, serum testosterone levels, and basal nitrate generation were determined. Immunoexpression of endothelial NO synthase (eNOS) and inducible NO synthase (iNOS) was also accessed.
  
  
  RESULTS
  Ethanol intake for 4 weeks significantly increased noradrenergic nerve-mediated contractions of CSM in response to EFS. The endothelium-dependent relaxation induced by acetylcholine decreased after the ethanol treatment. Ethanol consumption decreased serum testosterone levels but did not affect the nitrate levels on rat CSM. The mRNA and protein levels for eNOS and iNOS receptors were increased in CSM from ethanol-treated rats.
  
  
  CONCLUSIONS
  Ethanol consumption reduces endothelium-dependent relaxation induced by acetylcholine, but does not affect SNP or EFS-induced relaxation, suggesting that ethanol disrupts the endothelial function. Despite the overexpression of eNOS and iNOS in ethanol-treated rats, the impaired relaxation induced by acetylcholine may suggest that chronic ethanol consumption induces endothelial dysfunction.
authors.affiliation: Department of Surgery and Anatomy, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Fermino S
authors.initials: FS
authors.lastname: Lizarte
authors.forename: Mario A
authors.initials: MA
authors.lastname: Claudino
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Tirapelli
authors.forename: Marcelo
authors.initials: M
authors.lastname: Morgueti
authors.forename: Daniela P C
authors.initials: DP
authors.lastname: Tirapelli
authors.forename: Marcelo E
authors.initials: ME
authors.lastname: Batalhão
authors.forename: Evelin C
authors.initials: EC
authors.lastname: Carnio
authors.forename: Regina H
authors.initials: RH
authors.lastname: Queiroz
authors.forename: Paulo R B
authors.initials: PR
authors.lastname: Evora
authors.forename: Silvio
authors.initials: S
authors.lastname: Tucci
authors.forename: Adauto
authors.initials: A
authors.lastname: Cologna
authors.forename: Edson
authors.initials: E
authors.lastname: Antunes
authors.forename: Antonio C P
authors.initials: AC
authors.lastname: Martins
authors.forename: Luis F
authors.initials: LF
authors.lastname: Tirapelli
mesh_terms: D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D008297:Male; D009130:Muscle, Smooth / Q000503:physiopathology*; D009569:Nitric Oxide / Q000502:physiology; D010413:Penis / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009569:Nitric Oxide