Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 21, 2019; 25(39): 5953-5960
Published online Oct 21, 2019. doi: 10.3748/wjg.v25.i39.5953
Gender differences in vascular reactivity of mesenteric arterioles in portal hypertensive and non-portal hypertensive rats
Bin Zhang, Lin-Hua Ji, Cheng-Gang Zhang, Gang Zhao, Zhi-Yong Wu
Bin Zhang, Lin-Hua Ji, Cheng-Gang Zhang, Gang Zhao, Zhi-Yong Wu, Department of Gastrointestinal Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
Author contributions: Zhang B, Zhao G, and Wu ZY designed the research; Ji LH, Zhang B, and Zhang CG performed the research; Zhang B and Zhang CG analyzed the data; Ji LH and Zhang B wrote the paper.
Supported by the National Natural Science Foundation for the Youth of China, No. 81400630
Institutional review board statement: The study was reviewed and approved by Renji Hospital Institutional Review Board.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of Renji Hospital (IACUC protocol number: RJ-20151211).
Conflict-of-interest statement: The authors declare that there is no conflict of interest to be disclosed.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The ARRIVE Guidelines have been adopted.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Gang Zhao, MD, PhD, Chief Doctor, Surgeon, Department of Gastrointestinal Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160 Pujian Road, Shanghai 200127, China. zhaogang@renji.com
Telephone: +86-21-68383732 Fax: +86-21-68383090
Received: July 25, 2019
Peer-review started: July 25, 2019
First decision: August 17, 2019
Revised: August 28, 2019
Accepted: September 9, 2019
Article in press: September 9, 2019
Published online: October 21, 2019
Processing time: 87 Days and 21.2 Hours
Abstract
BACKGROUND

Portal hypertension (PHT) is primarily caused by an increase in resistance to portal outflow and secondarily by an increase in splanchnic blood flow. Vascular hyporeactivity both in systemic circulation and in the mesenteric artery plays a role in the hyperdynamic circulatory syndrome.

AIM

To explore gender differences and the role of endogenous sex hormones in PHT and vascular reactivity of mesenteric arterioles in rats.

METHODS

Cirrhosis and PHT were established by subcutaneous injection of carbon tetrachloride (CCl4) in both male and female integral and castrated rats (ovariectomized [OVX] in female rats, orchiectomy [ORX] in male rats). The third-order branch of the mensenteric artery was divided and used to measure vascular reactivity to vasoconstrictors.

RESULTS

No significant difference in portal pressure was observed between integral and castrated male PHT rats (15.2 ± 2.1 mmHg vs 16.7 ± 2.7 mmHg, P > 0.05). The portal pressure in integral female PHT rats was lower than that in OVX female PHT rats (12.7 ± 2.7 mmHg vs 16.5 ± 2.4 mmHg, P < 0.05). In PHT rats, the concentration response curves of the mesenteric arterioles to norepinephrine were shifted to the right, and the maximal responses (Emax) values were decreased and effective concentrations causing half maximum responses (EC50) values were increased, compared to those of non-PHT rats, both in male and female rats. Compared to non-PHT integral male rats, the sensitivity of the mesenteric arterioles of non-PHT ORX male rats to norepinephrine was decreased (P > 0.05). However, there was no difference between integral and ORX male rats with PHT. In integral female PHT rats, the concentration response curves were shifted to the left (P < 0.05), and the Emax values were increased and EC50 values were decreased compared to OVX female PHT rats.

CONCLUSION

Clear gender differences were observed in mesenteric vascular reactivity in CCl4-induced cirrhotic and PHT rats. Conservation of estrogen can retain the sensitivity of the mesenteric arterioles to vasoconstrictors and has a protective effect on splanchnic vascular function in PHT.

Keywords: Portal hypertension; Vascular reactivity; Gender; Estrogen; Liver cirrhosis

Core tip: In cirrhosis, extrahepatic vascular hypocontractility leads to splanchnic vasodilation and decreased splanchnic vascular resistance. In this study, clear gender differences were observed in mesenteric vascular reactivity in carbon tetrachloride-induced cirrhotic and portal hypertensive rats. Conservation of estrogen can retain the sensitivity of mesenteric arterioles to vasoconstrictors and has a protective effect on splanchnic vascular function in portal hypertension.