title: Estrogen improves the hyperdynamic circulation and hyporeactivity of mesenteric arteries by alleviating oxidative stress in partial portal vein ligated rats.
abstract: OBJECTIVE
  To evaluate the effects of estrogen (E2) on systemic and splanchnic hyperdynamic circulation in portal hypertensive rats.
  
  
  METHODS
  Fifty castrated female Sprague-Dawley rats were divided into five groups: sham operation (SO), partial portal vein ligation (PPVL) + placebo (PLAC), PPVL + E2, PPVL + ICI and PPVL + E2 + ICI. Hemodynamic measurements were performed using ultrasonography. Mesenteric arteriole contractility in response to norepinephrine was determined using a vessel perfusion system. Oxidative stress in the mesenteric artery was investigated by in situ detection of the superoxide anion (O2•(-)) and hydrogen peroxide (H2O2) concentrations.
  
  
  RESULTS
  Treatment with E2 resulted in a significant decrease of portal pressure (P < 0.01) and portal venous inflow (P < 0.05), and higher systemic vascular resistance (P < 0.05) and splanchnic arteriolar resistance (P < 0.01) in PPVL + E2 rats compared to PPVL + PLAC rats. In the mesenteric arterioles of PPVL + E2 rats, the dose-response curve was shifted left, and the EC50 was decreased (P < 0.01). E2 reduced O2•(-) production and H2O2 concentration in the mesenteric artery. However, ICI182, 780 reversed the beneficial effects of E2, therefore, the systemic and splanchnic hyperdynamic circulation were more deteriorated in ICI182, 780-treated rats.
  
  
  CONCLUSIONS
  Treatment with estrogen improved the systemic and splanchnic hyperdynamic circulation in PPVL rats, in part due to the alleviation of oxidative stress.
authors.affiliation: Bin Zhang, Cheng-Gang Zhang, Quan-Bo Zhou, Wei Chen, Zhi-Yong Wu, Department of General Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Cheng-Gang
authors.initials: CG
authors.lastname: Zhang
authors.forename: Quan-Bo
authors.initials: QB
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Wu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001160:Arterioles / Q000187:drug effects / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D005260:Female; D000077267:Fulvestrant; D006439:Hemodynamics / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000378:metabolism; D006975:Hypertension, Portal / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008026:Ligation; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects*; D017082:Portal Pressure / Q000187:drug effects; D011169:Portal Vein / Q000187:drug effects* / Q000503:physiopathology / Q000601:surgery*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013152:Splanchnic Circulation / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000975:Antioxidants; D004965:Estrogen Antagonists; D013481:Superoxides; D000077267:Fulvestrant; D004958:Estradiol; D006861:Hydrogen Peroxide
keywords: Estrogen; Hyperdynamic circulation; Oxidative stress; Partial portal vein ligation