Inducing Acute Liver Injury in Rats via Carbon Tetrachloride (CCl4) Exposure Through an Orogastric Tube

Summary

This protocol describes a common and feasible method of inducing acute liver injury (ALI) via CCl₄ exposure through an orogastric tube. CCl₄ exposure induces ALI through the formation of reactive oxygen species during its biotransformation in the liver. This method is used to analyze the pathophysiology of ALI and examine different hepatoprotective strategies.

Abstract

Acute liver injury (ALI) plays a crucial role in the development of hepatic failure, which is characterized by severe liver dysfunction including complications such as hepatic encephalopathy and impaired protein synthesis. Appropriate animal models are vital to test the mechanism and pathophysiology of ALI and investigate different hepatoprotective strategies. Due to its ability to perform chemical transformations, carbon tetrachloride (CCl₄) is widely used in the liver to induce ALI through the formation of reactive oxygen species. CCl₄ exposure can be performed intraperitoneally, by inhalation, or through a nasogastric or orogastric tube. Here, we describe a rodent model, in which ALI is induced by CCl₄ exposure through an orogastric tube. This method is inexpensive, easily performed, and has minimal hazard risk. The model is highly reproducible and can be widely used to determine the efficacy of potential hepatoprotective strategies and assess markers of liver injury.

Introduction

The frequency of toxic insults to the liver, especially due to alcohol and drug abuse, is increasing. Acute liver injury (ALI) is associated with high mortality rates and has caused clinical concerns^1,2. Toxic injury leads to death signaling pathways in the liver, resulting in hepatocyte apoptosis, necrosis, or pyroptosis. ALI plays a crucial role in the development of hepatic failure, which is characterized by severe liver dysfunction including complications such as hepatic encephalopathy and impaired protein synthesis^3,4. Although recent research has....

Protocol

The experiments were conducted according to the recommendations of the Declarations of Helsinki and Tokyo and to the Guidelines for the Use of Experimental Animals of the European Community. The experiments were approved by the Animal Care Committee of Ben-Gurion University of the Negev.

NOTE: The CCl₄ model has been generated and used in a previous study¹⁷. The protocol timeline is demonstrated in Table 1.

1. Preparing rats for the experimental procedure

NOTE: Select adult male Sprague Dawley rats weighing 300−350 g.

Results

The TB, GOT, and GPT levels significantly increased 24 h after inducing ALI (more at higher CCl₄ doses) compared to sham-operated controls (p < 0.001) (Figure 1). The levels of TB, GOT, and GPT at baseline were normal and were not significantly different than sham-operated controls. At 24 h, all three interventional groups, 1 mL/kg CCl₄ (1, 1−2), 2.5 mL/kg CCl₄ (3, 3−4), and 5 mL/kg CCl₄ (4, 4−5.75), had a significantly higher histological gradi.......

Discussion

In this protocol, CCl₄ is used as a liver toxin to induce ALI in rats. ALI is characterized by loss of hepatic parenchyma and subsequent dysregulation of the liver’s metabolic and synthetic functions. Drugs, viruses, toxins, autoimmune diseases, metabolic diseases, and vascular disorders all induce hepatocyte death, and the subsequent inflammatory response contributes to the pathogenesis of ALI.

The initial insult to the liver leads to cytokine production, chemokine release, a.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
22 G catheter BD Neoflon TM	Becton Dickinson Infusion Therapy AB
4% buffered formaldehyde solution	Sigma - Aldrich lab materials technologies
BD Microtainer SST TM Tubes	Becton Dickinson and Company
Carbone tetrachloride	Sigma - Aldrich lab materials technologies	CAS 56-23-5
Isofluran, USP 100%	Piramamal Critical Care, Inc
Olympus AU2700 Chemistry-Immuno Analyzer	Olympus (MN, USA)		Analysis of blood samples was done by the fluorescence method
Olympus BX 40 microscope	Olympus
RAT Feeding Needles	ORCHID SCIENTIFICS
SYRINGE SET 1 and 2 ml MEDI -PLUS	Shandong Zibo Shanchuan Medical Instruments Co., Ltd