Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2017; 23(23): 4191-4199
Published online Jun 21, 2017. doi: 10.3748/wjg.v23.i23.4191
Induction of chronic cholestasis without liver cirrhosis - Creation of an animal model
Felix Dondorf, René Fahrner, Michael Ardelt, Eleonora Patsenker, Felix Stickel, Uta Dahmen, Utz Settmacher, Falk Rauchfuß
Felix Dondorf, René Fahrner, Michael Ardelt, Uta Dahmen, Utz Settmacher, Falk Rauchfuß, Department of General, Visceral and Vascular Surgery, Jena University Hospital, 07747 Jena, Germany
Eleonora Patsenker, Felix Stickel, Division of Gastroenterology and Hepatology, University Hospital Zürich, 8091 Zürich, Switzerland
Author contributions: Dondorf F, Settmacher U and Rauchfuß F designed the study; Dondorf F, Fahrner R, Patsenker E, Stickel F, Dahmen U and Rauchfuß F performed the data acquisition; Dondorf F, Settmacher U and Rauchfuß F analyzed the data; Dondorf F and Rauchfuß F wrote the paper; Fahrner R, Ardelt M, Settmacher U and Rauchfuß F revised the paper.
Institutional review board statement: Since this study is an animal research project, an institutional review board statement is not needed in our institution.
Institutional animal care and use committee statement: All animal experiments were approved by the Thuringian State Office of Food Safety and Consumer Protection (Department Consumer Protection, Veterinary and Pharmacy, Bad Langensalza, Germany). Protocol number: 02-039/12.
Conflict-of-interest statement: All authors have no conflicts of interest or financial ties to disclose.
Data sharing statement: The technical appendix and dataset are available from the corresponding author at felix.dondorf@med.uni-jena.de.
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: Falk Rauchfuß, MD, MSc, Department of General, Visceral and Vascular Surgery, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany. falk.rauchfuss@med.uni-jena.de
Telephone: +49-3641-9322601 Fax: +49-3641-9322602
Received: December 27, 2016
Peer-review started: December 28, 2016
First decision: February 10, 2017
Revised: February 27, 2017
Accepted: May 9, 2017
Article in press: May 9, 2017
Published online: June 21, 2017
Processing time: 174 Days and 15.3 Hours
Abstract
AIM

To analyze time intervals of inflammation and regeneration in a cholestatic rat liver model.

METHODS

In 36 Lewis rats, divided into six groups of 6 animals (postoperative observation periods: 1, 2, 3, 4, 6, 8 wk), the main bile duct was ligated with two ligatures and observed for the periods mentioned above. For laboratory evaluation, cholestasis parameters (bilirubin, γ-GT), liver cell parameters (ASAT, ALAT) and liver synthesis parameters (quick, albumin) were determined. For histological analysis, HE, EvG, ASDCL and HMGB-1 stainings were performed. Furthermore, we used the mRNA of IL-33, GADD45a and p-21 for analyzing cellular stress and regeneration in cholestatic rats.

RESULTS

In chemical laboratory and histological evaluation, a distinction between acute and chronic cholestatic liver injury with identification of inflammation and regeneration could be demonstrated by an increase in cholestasis (bilirubin: 1-wk group, 156.83 ± 34.12 μmol/L, P = 0.004) and liver cell parameters (ASAT: 2-wk group, 2.1 ± 2.19 μmol/L.s, P = 0.03; ALAT: 2-wk group, 1.03 ± 0.38 μmol/L.s, P = 0.03) after bile duct ligation (BDL). Histological evaluation showed an increase of bile ducts per portal field (3-wk group, 48 ± 6.13, P = 0.004) during the first four weeks after bile duct ligation. In addition to inflammation, which is an expression of acute cholestasis, there was an increase of necrotic areas in the histological sections (2-wk group, 1.38% ± 2.28% per slide, P = 0.002). Furthermore, the inflammation could be verified by ASDCL (4-wk group, 22 ± 5.93 positive cells per portal field, P = 0.041) and HMGB-1 [2-wk group, 13 ± 8.18 positive cells per field of view (FoV), P = 0.065] staining. Therefore, in summary of the laboratory evaluation and histological studies, acute cholestasis could be found during the first four weeks after bile duct ligation. Subsequently, the described parameters declined so that chronic cholestasis could be assumed. For quantification of secondary biliary cirrhosis, eosin staining was performed, which did not reveal any signs of liver remodeling, thus precluding the development of a chronic cholestasis model. Additionally, to establish the chronic cholestasis model, we evaluated liver regeneration capacity through measurements of IL-33, p-21 and GADD45a mRNA.

CONCLUSION

We created a chronic cholestasis model. The point of inflammatory and regenerative balance was reached after four weeks. This finding should be used for experimental approaches dealing with chronic cholestatic liver damage.

Keywords: Rats; Cholestasis; Chronic cholestasis; Rat liver model

Core tip: Animal research models mostly address either acute cholestasis or secondary biliary cirrhosis, neither of which reflect the clinical reality of central liver tumors with cholestatic liver damage without secondary liver cirrhosis. In this work, we present our data from a model simulating chronic cholestatic liver damage in an otherwise healthy liver.