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If you ever wondered how your drugs, medications and other ingested products get detoxified in the body, ask the liver. And if you ever asked yourself where our body assembles amino acids to make proteins when needed, check the liver. And in the event that you were wondering how your blood sugar remains controlled even when you fast or spend several hours or days without eating, you should again ask your liver.
It plays a central role in digestion (with the emulsification of fats (with the secretion of bile), drugs and toxin metabolism (with the function of the microsome P450 system), formation of proteins with amino acids and regulation of blood sugar with processes such as gluconeogenesis and glycogenolysis. Henceforth, diseases that affect the liver would impair more than that single organ: they would affect the entire body in general.
The most common types of liver diseases include:
- Fatty liver disease
- Portal hypertension
- Liver cirrhosis
- Liver cancer
Interestingly enough, although those diseases can be considered as individual entities, more often than not they can also progress from one state to the other.
Fatty Liver disease
Fatty liver disease is a metabolic state of temporary damage in which large vacuoles of fat (triglycerides) accumulate within the hepatocytes (liver cells) secondary to a toxic stimuli. Generally, this state of disease is reversible as the cellular architecture and the most important components are not damaged. With that said, removal of the toxic stimulus causes reversal of the metabolic state and return of the cells to normal. At a cellular level, the problem that causes fatty liver disease is a defect in fatty acid metabolism.
This can be due to either decreased energy consumption and combustion (maybe because there is not enough energy to process the fatty acids or we consume more fatty acids that can be processed at a time), or because of increased peripheral resistance to insulin, which also plays a crucial role in fatty acid metabolism. Fatty liver diseases has several causes, ranging from drugs and toxins, infections, nutritional or inflammatory states.
However, the two most common causes (which we will discuss here) are alcoholism and obesity. In alcoholism for instance, the excess alcohol consumption causes toxic damage to the mitochondria which are the energy source of the cells, causing decreased energy for the metabolism of fats. In obesity, there is peripheral resistance to the effects of insulin, which also leads to increased fat storage. In both instances, the neutral fats first start to accumulate in the cytoplasm, around the nucleus, forming small vacuoles. This is called microvesicular changes. As the extent of the damage advances, more and more fats accumulate, thus occupying a larger surface area and eventually pushing the cellular nuclei at the periphery, giving the entire cell a characteristic appearance called “signet ring”. This is referred to as “macrovesicular changes”. Fatty liver disease on its own is asymptomatic, but if it progresses to another stage, you could start experiencing symptoms of liver damage.