title: The in vitro effects of clonidine and dexmedetomidine on human myometrium.
abstract: BACKGROUND
  alpha(2)-adrenergic agonists have been used extensively in the field of anaesthesia. Their direct effect on the human myometrium was investigated in this in vitro study, as this may have clinical repercussions in obstetric anaesthesia.
  
  
  METHODS
  Strips of pregnant human myometrium obtained from six individuals at elective caesarean section were mounted on the Mulvany myograph in Krebs solution to which increasing concentrations of clonidine and dexmedetomidine (1x10(-11) to 1x10(-6) g/mL) were added.
  
  
  RESULTS
  Dexmedetomidine increased uterine contractility at simulated clinical plasma concentrations (1x10(-9) g/mL). These effects were seen with clonidine only at much higher tissue bath concentrations (1x10(-7) g/mL).
  
  
  CONCLUSIONS
  The effect of dexmedetomidine on human myometrium has profound implications in obstetric anaesthesia and needs further clinical investigation.
authors.affiliation: Department of Anaesthesia, Division of Obstetrics and Gynaecology, KK Women's and Children's Hospital, Singapore. athsia@kkh.com.sg
authors.forename: A T
authors.initials: AT
authors.lastname: Sia
authors.forename: K
authors.initials: K
authors.lastname: Kwek
authors.forename: G S
authors.initials: GS
authors.lastname: Yeo
mesh_terms: D003000:Clonidine / Q000494:pharmacology*; D020927:Dexmedetomidine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009215:Myometrium / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy / Q000502:physiology*; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D020927:Dexmedetomidine; D003000:Clonidine