Discover the Mechanisms of Liver Injury

Types of Liver Injury and Their Mechanisms

• Toxicants can induce various toxic effects on different organelles in liver cells through biochemical reactions.
• The mechanisms of liver injury include lipid peroxidation, covalent binding, protein synthesis inhibition, biliary production/flow disturbance, immunologic reaction, and calcium homeostasis perturbation.
• Fatty liver is a liver that contains more than 5% lipid by weight, induced by ethanol, methotrexate, tetracycline, or other toxicants.
• Liver necrosis involves the death of hepatocytes and can be focal or massive, induced by carbon tetrachloride, chloroform, phosphorus, acetaminophen, isoniazid, iproniazid, and other toxicants.
• Cholestasis is a less common type of liver damage, usually acute, induced by ethinyl estradiol, anabolic and contraceptive steroids, chlorpromazine, erythromycin lactobionate, and other toxicants.
• Cirrhosis is characterized by the presence of septae of collagen throughout most of the liver, induced by several chemical carcinogens, long-term administration of CC74, and chronic ingestion of alcoholic beverages.
• The mechanism of cirrhosis is not fully understood, but ethanol may damage mitochondria and increase local production of reactive oxygen species, leading to steatosis, necrosis, and cirrhosis.
• Ethanol-induced cirrhosis in animals requires a combination of ethanol and diets deficient in choline, proteins, methionine, vitamin B12, and folic acid.
• Fatty liver can occur due to inhibition of lipoprotein synthesis, reduced conjugation of triglyceride with lipoproteins, and loss of potassium from hepatocytes.
• Early morphologic changes in liver necrosis include cytoplasmic edema, dilatation of endoplasmic reticulum, and disaggregation of polysomes.
• Late changes in liver necrosis are progressive swelling of mitochondria and cytoplasm, dissolution of organelles and nucleus, and rupture of plasma membrane.
• Carbon tetrachloride acts primarily through its reactive metabolite, the trichloromethyl radical CC13, which covalently binds with proteins and unsaturated lipids and induces lipid peroxidation, leading to a disturbance of liver cell Ca homeostasis and cell death.

Test your knowledge on the various types of liver injury and their mechanisms with this informative quiz. From toxicants inducing toxic effects on liver cells to the different types of liver damage such as fatty liver, liver necrosis, cholestasis, and cirrhosis, this quiz covers it all. Learn about the biochemical reactions that cause these injuries and the specific toxicants that induce them. Take this quiz to enhance your understanding of liver injury and its mechanisms.