title: Coupling of α1-adrenoceptors to ERK1/2 in the human prostate.
abstract: BACKGROUND
  α1-Adrenoceptors are considered critical for the regulation of prostatic smooth muscle tone. However, previous studies suggested further α1-adrenoceptor functions besides contraction. Here, we investigated whether α1-adrenoceptors in the human prostate may activate extracellular signal-regulated kinases (ERK1/2).
  
  
  METHODS
  Prostate tissues from patients undergoing radical prostatectomy were stimulated in vitro. Activation of ERK1/2 was assessed by Western blot analysis. Expression of ERK1/2 was studied by immunohistochemistry. The effect of ERK1/2 inhibition by U0126 on phenylephrine-induced contraction was studied in organ-bath experiments.
  
  
  RESULTS
  Stimulation of human prostate tissue with noradrenaline (30 μM) or phenylephrine (10 μM) resulted in ERK activation. This was reflected by increased levels of phosphorylated ERK1/2. Expression of ERK1/2 in the prostate was observed in smooth muscle cells. Incubation of prostate tissue with U0126 (30 μM) resulted in ERK1/2 inhibition. Dose-dependent phenylephrine-induced contraction of prostate tissue was not modulated by U0126.
  
  
  CONCLUSIONS
  α1-Adrenoceptors in the human prostate are coupled to ERK1/2. This may partially explain previous observations suggesting a role of α1-adrenoceptors in the regulation of prostate growth.
authors.affiliation: Department of Urology, University of Munich, Germany.
authors.forename: Ricarda M
authors.initials: RM
authors.lastname: Bauer
authors.forename: Frank
authors.initials: F
authors.lastname: Strittmatter
authors.forename: Christian
authors.initials: C
authors.lastname: Gratzke
authors.forename: Johanna
authors.initials: J
authors.lastname: Göttinger
authors.forename: Boris
authors.initials: B
authors.lastname: Schlenker
authors.forename: Oliver
authors.initials: O
authors.lastname: Reich
authors.forename: Christian G
authors.initials: CG
authors.lastname: Stief
authors.forename: Petter
authors.initials: P
authors.lastname: Hedlund
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Andersson
authors.forename: Martin
authors.initials: M
authors.lastname: Hennenberg
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology; D002070:Butadienes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D008954:Models, Biological; D009570:Nitriles / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010766:Phosphorylation; D011467:Prostate / Q000187:drug effects / Q000201:enzymology*; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D014551:Urinary Tract / Q000378:metabolism
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D018340:Receptors, Adrenergic, alpha-1; C113580:U 0126; D010656:Phenylephrine; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D009638:Norepinephrine