title: Estradiol administration after trauma-hemorrhage improves cardiovascular and hepatocellular functions in male animals.
abstract: OBJECTIVE
  To determine whether female sex steroids have any salutary effects on the depressed cardiovascular and hepatocellular functions following trauma and hemorrhage in male animals.
  
  
  BACKGROUND
  Studies indicate that gender difference exists in the immune and cardiovascular responses to trauma-hemorrhage, and that male sex steroids appear to be responsible for producing immune and organ dysfunction, but it remains unknown if female sex steroids produce any salutary effects on the depressed cellular and organ functions in males following trauma and hemorrhage.
  
  
  METHODS
  Adult male Sprague-Dawley rats underwent a midline laparotomy (i.e., trauma induction), and were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of the maximum bleed-out volume was returned in the form of Ringer's lactate (RL). Animals were then resuscitated with RL at 4 times the shed blood over 60 minutes. 17beta-estradiol (50 microg/kg) or an equal volume of vehicle was injected subcutaneously 15 minutes before the end of resuscitation. The maximal rate of ventricular pressure increase or decrease (+/-dP/dtmax), cardiac output, and hepatocellular function (i.e., maximal velocity and overall efficiency of in vivo indocyanine green clearance) were assessed at 24 hours after hemorrhage and resuscitation. Plasma levels of interleukin (IL)-6 were also measured.
  
  
  RESULTS
  Left ventricular performance, cardiac output, and hepatocellular function decreased significantly at 24 hours after trauma-hemorrhage and resuscitation. Plasma levels of IL-6 were elevated. Administration of 17beta-estradiol significantly improved cardiac performance, cardiac output, and hepatocellular function, and attenuated the increase in plasma IL-6 levels.
  
  
  CONCLUSIONS
  Administration of estrogen appears to be a useful adjunct for restoring cardiovascular and hepatocellular functions after trauma-hemorrhage in male rats.
authors.affiliation: Center for Surgical Research and Department of Surgery, Brown University School of Medicine and Rhode Island Hospital, Providence, Rhode Island, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Mizushima
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Jarrar
authors.forename: W G
authors.initials: WG
authors.lastname: Cioffi
authors.forename: K I
authors.initials: KI
authors.lastname: Bland
authors.forename: I H
authors.initials: IH
authors.lastname: Chaudry
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002302:Cardiac Output / Q000187:drug effects; D004396:Coloring Agents / Q000493:pharmacokinetics; D004958:Estradiol / Q000494:pharmacology / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects*; D006470:Hemorrhage / Q000188:drug therapy* / Q000503:physiopathology*; D007208:Indocyanine Green / Q000493:pharmacokinetics; D015850:Interleukin-6 / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012044:Regression Analysis; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D014947:Wounds and Injuries / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D004396:Coloring Agents; D015850:Interleukin-6; D004958:Estradiol; D007208:Indocyanine Green