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©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 21, 2019; 25(3): 346-355
Published online Jan 21, 2019. doi: 10.3748/wjg.v25.i3.346
Effects of positive acceleration (+Gz stress) on liver enzymes, energy metabolism, and liver histology in rats
Bin Shi, Xian-Qiang Wang, Wei-Dong Duan, Guo-Dong Tan, Han-Jing Gao, Ying-Wei Pan, Qing-Jun Guo, Hong-Yi Zhang
Bin Shi, Hong-Yi Zhang, Department of Hepatobiliary Surgery, Air Force Medical Center, PLA, Beijing 100142, China
Xian-Qiang Wang, Department of Pediatrics, Chinese PLA General Hospital and PLA Medical School, Beijing 100853, China
Wei-Dong Duan, Ying-Wei Pan, Department of Hepatobiliary Surgery, Chinese PLA General Hospital and PLA Medical School, Beijing 100853, China
Guo-Dong Tan, Outpatient Department, Air Command Headquarters, Beijing 100038, China
Han-Jing Gao, Department of Ultrasound, Chinese PLA General Hospital and PLA Medical School, Beijing 100853, China
Qing-Jun Guo, Department of Endocrinology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Author contributions: Zhang HY and Shi B designed the research; Shi B, Wang XQ, and Duan WD performed the research; Shi B, Tan GD, and Gao HJ contributed new reagents or analytic tools; Shi B, Pan YW, and Guo QJ analyzed the data; Shi B and Zhang HY wrote the paper.
Supported by the China Post-doctoral Science Foundation Project, No. 2018T111151.
Institutional review board statement: This study was reviewed and approved by the Chinese PLA Air Force Medical Center Institutional Review Board.
Institutional animal care and use committee statement: This study was reviewed and approved by the Chinese PLA Air Force Medical CenterInstitutional animal care and use committee.
Conflict-of-interest statement: The authors declare that there are no conflicts of interest to disclose.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: This paper was prepared according to the ARRIVE guidelines.
Open-Access: This is an open-access article that 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: Hong-Yi Zhang, MD, Professor, Department of Hepatobiliary Surgery, Air Force Medical Center, PLA, No. 30, Fucheng Road, Haidian District, Beijing 100142, China. qhcgzhy@163.com
Telephone: +86-10-66928312 Fax: +86-10-66928312
Received: October 30, 2018
Peer-review started: October 30, 2018
First decision: November 14, 2018
Revised: December 12, 2018
Accepted: December 21, 2018
Article in press: December 21, 2018
Published online: January 21, 2019
BACKGROUND
Exposure to high sustained +Gz (head-to-foot inertial load) is known to have harmful effects on pilots’ body in flight. Although clinical data have shown that liver dysfunction occurs in pilots, the precise cause has not been well defined.
AIM
To investigate rat liver function changes in response to repeated +Gz exposure.
METHODS
Ninety male Wistar rats were randomly divided into a blank control group (BC group, n = 30), a +6 Gz/5 min stress group (6GS group, n = 30), and a +10 Gz/5min stress group (10GS group, n = 30). The 6GS and 10GS groups were exposed to +6 Gz and +10 Gz, respectively, in an animal centrifuge. The onset rate of +Gz was 0.5 G/s. The sustained time at peak +Gz was 5 min for each exposure (for 5 exposures, and 5-min intervals between exposures for a total exposure and non-exposure time of 50 min). We assessed liver injury by measuring the portal venous flow volume, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver tissue malondialdehyde (MDA), Na+-K+-ATPase, and changes in liver histology. These parameters were recorded at 0 h, 6 h, and 24 h after repeated +Gz exposures.
RESULTS
After repeated +Gz exposures in the 6GS and the 10GS groups, the velocity and flow signal in the portal vein (PV) were significantly decreased as compared to the BC group at 0 h after exposure. Meanwhile, we found that the PV diameter did not change significantly. However, rats in the 6GS group had a much higher portal venous flow volume than the 10GS group at 0 h after exposure. The 6GS group had significantly lower ALT, AST, and MDA values than the 10GS group 0 h and 6 h post exposure. The Na+-K+-ATPase activity in the 6GS group was significantly higher than that in the 10GS group 0 h and 6 h post exposure. Hepatocyte injury, determined pathologically, was significantly lower in the 6GS group than in the 10GS group.
CONCLUSION
Repeated +Gz exposures transiently cause hepatocyte injury and affect liver metabolism and morphological structure.
Core tip: Some clinical data showed that liver dysfunction was observed in pilots. However, the reason was not clear. We conducted this experimental study to investigate rat liver function changes in response to repeated +Gz exposures, and to observe the portal venous flow volume, liver function indexes, liver tissue malondialdehyde, Na+-K+-ATPase activity, and changes in liver histology. We found that repeated +Gz exposures transiently cause hepatocyte injury and affect liver metabolism and morphological structure.
