title: Change in morphology and oxytocin receptor expression in the uterine blood vessels during the involution process.
abstract: BACKGROUND
  The histological changes in uterine blood vessels during pregnancy have been well investigated, but there have been few reports focusing on the changes in blood vessels during the involution process, especially within the first 24 h. We observed the process of uterine involution, focusing on the vessels of the resected uterus.
  
  
  METHODS
  Paraffin-embedded uterine samples from 15 patients who underwent hysterectomy because of severe cervical laceration and uterine rupture were examined. The time between delivery and hysterectomy ranged from 15 min to 456 h. The specimens were stained with hematoxylin-eosin, elastica-van Gieson and an antioxytocin receptor antibody.
  
  
  RESULTS
  Changes in the uterine vessels varied substantially based on their location. The intima in arteries of the endometrial side thickened within 5 h after delivery. On the serosal side, phlebosclerosis was demonstrated 6 weeks postpartum. Immunoreactivity for the oxytocin receptor (OTR) appeared in the muscular medias of arteries 5 h after delivery although it was not expressed before this period.
  
  
  CONCLUSIONS
  Remodeling of uterine vessels involved thickening of the arterial intima and OTR expression in vessel walls during the first 5 h postpartum; the parameters normalized within 6 weeks. However, phlebosclerosis persisted for a long time on the serosal side.
authors.affiliation: Department of Diagnostic Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Wakasa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Wakasa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakayama
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kuwae
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsuoka
authors.forename: Makoto
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Suehara
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kimura
mesh_terms: D000328:Adult; D001158:Arteries / Q000378:metabolism* / Q000473:pathology*; D001707:Biopsy, Needle; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007044:Hysterectomy / Q000379:methods; D007150:Immunohistochemistry; D007744:Obstetric Labor Complications / Q000473:pathology*; D006473:Postpartum Hemorrhage / Q000473:pathology / Q000601:surgery; D011247:Pregnancy; D018045:Receptors, Oxytocin / Q000378:metabolism*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D019687:Uterine Inversion / Q000473:pathology*; D014599:Uterus / Q000098:blood supply* / Q000473:pathology*
chemical_list: D018045:Receptors, Oxytocin