title: Clinical significance of melatonin receptors in the human myometrium.
abstract: OBJECTIVE
  To review and update the research on melatonin receptor expression in the human myometrium, in particular as it pertains to uterine contractility at labor.
  
  
  METHODS
  Summary of previous studies with the addition of new data on the transcriptional regulation of melatonin receptor expression in human myometrial cells.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Late-term pregnant volunteers.
  
  
  METHODS
  Biopsy collection for in vitro analyses provided the original data. More recently, uterine contractions in late-term pregnant volunteers were assessed before, during, and after acute white-light exposure.
  
  
  METHODS
  Melatonin receptor signaling in myometrial cells and uterine contractions in late-term pregnant volunteers.
  
  
  RESULTS
  Melatonin acts through the MTNR1B melatonin receptor that is expressed in the myometrium at late term to synergistically enhance oxytocin-dependent signaling and contractions. Acute inhibition of endogenous melatonin levels with light reversibly suppresses uterine contractions.
  
  
  CONCLUSIONS
  These results point to a significant role for circulating melatonin in the timing and degree of uterine contractions in late-term pregnancy. Understanding the regulation of melatonin receptors remains a future objective.
authors.affiliation: Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida. Electronic address: James.olcese@med.fsu.edu.
authors.forename: James
authors.initials: J
authors.lastname: Olcese
authors.affiliation: Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida.
authors.forename: Stephen
authors.initials: S
authors.lastname: Beesley
mesh_terms: D057906:Circadian Clocks; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008027:Light; D008550:Melatonin / Q000378:metabolism*; D009215:Myometrium / Q000378:metabolism* / Q000528:radiation effects; D010121:Oxytocin / Q000378:metabolism; D017440:Photoperiod; D011247:Pregnancy; D044094:Receptors, Melatonin / Q000378:metabolism* / Q000528:radiation effects; D015398:Signal Transduction; D013997:Time Factors; D014590:Uterine Contraction / Q000528:radiation effects
chemical_list: D044094:Receptors, Melatonin; D010121:Oxytocin; D008550:Melatonin
keywords: Myometrium; contractions; light; melatonin; receptors