Brief Article
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World J Gastroenterol. Oct 28, 2013; 19(40): 6863-6868
Published online Oct 28, 2013. doi: 10.3748/wjg.v19.i40.6863
Estrogen improves the hyperdynamic circulation and hyporeactivity of mesenteric arteries by alleviating oxidative stress in partial portal vein ligated rats
Bin Zhang, Cheng-Gang Zhang, Quan-Bo Zhou, Wei Chen, Zhi-Yong Wu
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
Author contributions: Zhang B, Chen W and Wu ZY designed research; Zhang B, Zhang CG and Zhou QB performed research; Zhang B and Zhang CG analyzed data; Zhang B and Zhou QB co-wrote the paper.
Correspondence to: Zhi-Yong Wu, MD, PhD, Department of General Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 1630 Dongfang Road, Shanghai 200127, China. zhiyongwu@gmail.com
Telephone: +86-21-68383732 Fax: +86-21-68383090
Received: June 29, 2013
Revised: August 18, 2013
Accepted: September 4, 2013
Published online: October 28, 2013
Processing time: 136 Days and 19 Hours
Abstract

AIM: 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.

CONCLUSION: Treatment with estrogen improved the systemic and splanchnic hyperdynamic circulation in PPVL rats, in part due to the alleviation of oxidative stress.

Keywords: Estrogen; Hyperdynamic circulation; Partial portal vein ligation; Oxidative stress

Core tip: Vascular hyporeactivity is affected by gender and estrogen. The aim of the present study was to investigate whether estrogen could attenuate the severity of hyperdynamic circulation and the underlying mechanism in pre-hepatic portal hypertensive rats without cirrhosis, with a focus on oxidative stress. The authors proposed that treatment with estrogen could improve the systemic and splanchnic hyperdynamic circulation in partial portal vein ligation rats, in part due to the alleviation of oxidative stress.