Liver cirrhosis: An overview of experimental models in rodents

Abstract

The liver, a component of the gastrointestinal tract, is one of the most important organs in the human body. The liver performs over 500 functions to promote physiological homeostasis. In addition, the liver acts as a screen, by metabolizing substances carried by blood coming from the digestive tract before they enter the systemic circulation. This vital function exposes the hepatic tissue to hepatotoxic agents, which can lead to liver damage if the organ's repair and regenerative capacity is insufficient. Several conditions such as persistent exposure to hepatitis C and B viruses, alcohol, and drugs can provoke this disbalance, eventually leading to liver cirrhosis, which is an irreversible and life-threatening condition. This paradigm of irreversibility began to be reconsidered when several studies showed that hepatic fibrosis is potentially reversible after cessation of exposure to the hepatotoxic agent or eradication of the primary disease. In the context of basic research in liver fibrosis and cirrhosis, it is essential to keep in mind that the capacity of the organ to recover spontaneously might be a significant limitation to long-term studies that use experimental models of liver cirrhosis. Here, we review animal models where liver cirrhosis is experimentally induced. We focus on a surgery-based model, i.e., bile duct ligation (BDL), and hepatotoxic drugs such as carbon tetrachloride (CCl 4), thioacetamide (TAA), and dimethylnitrosamine (DMN) administrated alone or in association with alcohol, the latter to potentialize the hepatotoxic effect of these agents. Also, we analyze the effects of these approaches, emphasizing the risks, spontaneous reversibility, and outcomes on animal health.