Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2015; 21(21): 6543-6549
Published online Jun 7, 2015. doi: 10.3748/wjg.v21.i21.6543
Low G preconditioning reduces liver injury induced by high +Gz exposure in rats
Bin Shi, Zhi-Qiang Feng, Wen-Bing Li, Hong-Yi Zhang
Bin Shi, Zhi-Qiang Feng, Wen-Bing Li, Hong-Yi Zhang, Department of Hepatobiliary Surgery, Chinese PLA Air Force General Hospital, Beijing 100142, China
Author contributions: Zhang HY and Shi B designed the research; Shi B and Li WB performed the research; Shi B and Feng ZQ analyzed the data; Shi B, Feng ZQ and Zhang HY wrote the paper.
Ethics approval: The study was reviewed and approved by the Chinese PLA Air Force General Hospital Institutional Review Board.
Conflict-of-interest: The authors declare there are no conflicts of interest to disclose.
Data sharing: No additional data are available.
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/
Correspondence to: Hong-Yi Zhang, MD, PhD, Department of Hepatobiliary Surgery, Chinese PLA Air Force General Hospital, No. 30 Fucheng Road, Beijing 100142, China. kjzygdwk@163.com
Telephone: +86-10-66928312 Fax: +86-10-66928312
Received: November 30, 2014
Peer-review started: November 30, 2014
First decision: January 8, 2015
Revised: February 4, 2015
Accepted: March 31, 2015
Article in press: March 31, 2015
Published online: June 7, 2015
Abstract

AIM: To investigate the effect of repeated lower +Gz exposure on liver injury induced by high +Gz exposure in rats.

METHODS: Sixty male Wister rats were randomly divided into a blank control group, a low G preconditioning group (LG) (exposed to +4 Gz/5 min per day for 3 d before +10 Gz/5 min exposure), and a +10 Gz/5 min group (10G) (n = 20 in each group). Blood specimens and liver tissue were harvested at 0 h and 6 h after +10 Gz/5 min exposure. Liver function was analyzed by measuring serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels, and liver injury was further assessed by histopathological observation. Malondialdehyde (MDA), superoxide dismutase (SOD) and Na+-K+-ATPase were determined in hepatic tissue.

RESULTS: The group LG had lower ALT, AST, and MDA values at 0 h after exposure than those in group 10G. SOD values and Na+-K+-ATPase activity in the LG group were higher than in group 10G 0 h post-exposure. Hepatocyte injury was significantly less in group LG than in group 10G on histopathological evaluation.

CONCLUSION: It is suggested that repeated low +Gz exposure shows a protective effect on liver injury induced by high +Gz exposure in rats.

Keywords: Positive acceleration (+Gz), Liver injury, Preconditioning, Animal centrifuge, Rat

Core tip: We conducted this experimental study to explore an optimized strategy of reducing liver injury induced by high +Gz exposure, and to observe more specific indices of liver function, such as alanine transaminase, aspartate aminotransferase, malondialdehyde, superoxide dismutase, Na+-K+-ATPase and hepatic pathology. We found that low G preconditioning reduced oxidative stress and significantly improved Na+-K+-ATPase activity, inducing minimal liver injury.