title: Biphasic effect of relaxin, inhibitable by a collagenase inhibitor, on the strength of human fetal membranes.
abstract: BACKGROUND
  Relaxin has been proposed as a hormone involved in the collagen remodeling of the utero-placental unit.
  
  
  METHODS
  Human fetal membrane explants were incubated with H1 or H2 relaxin for 48 hours and stretched until rupture in a materials testing machine. Co-incubation with a synthetic collagenase inhibitor was performed in order to examine whether the effects of relaxin could be inhibited. The effects on hydroxyproline and histology were evaluated.
  
  
  RESULTS
  Biomechanical testing showed that H2 relaxin induced a biphasic weakening of human fetal membranes, an effect that was abolished after co-incubation with a collagenase inhibitor. H1 relaxin produced no significant effects on the biomechanical properties. The effects of H2 relaxin on the biomechanical properties were, however, not followed by changes in the hydroxyproline concentration or the histology.
  
  
  CONCLUSIONS
  H2 relaxin had an effect on human fetal membranes and this effect may be mediated through collagenases.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of Aarhus, Skejby, DK-8200 Aarhus N, Denmark. idavogel@dadlnet.dk
authors.forename: Ida
authors.initials: I
authors.lastname: Vogel
authors.forename: Astrid
authors.initials: A
authors.lastname: Petersen
authors.forename: Lone Kjeld
authors.initials: LK
authors.lastname: Petersen
authors.forename: Rikke Bek
authors.initials: RB
authors.lastname: Helmig
authors.forename: Hans
authors.initials: H
authors.lastname: Oxlund
authors.forename: Niels
authors.initials: N
authors.lastname: Uldbjerg
mesh_terms: D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005321:Extraembryonic Membranes / Q000033:anatomy & histology / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D012065:Relaxin / Q000494:pharmacology*; D013718:Tensile Strength / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; C095067:RLN1 protein, human; C095068:RLN2 protein, human; D012065:Relaxin; D006909:Hydroxyproline