Question

What would be the metabolic effects of liver failure? Describe in detail. Discuss the pathways which will be affected and the effects on other organs of the body. Remember the many functions of the liver. (15)

Identify the many functions and pathways in the liver which will now be deficient. Both central metabolism and those of consequence to other tissues (5 pts).

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Identify materials/chemicals used by other organs/tissues which would be deficient, effects on the pathways of these other tissues and accumulation of toxins in the other tissues as a result of the liver biochemistry failure (5 pts).

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Overall effects on the other organs and tissues of the body (not the liver). Explain what liver failure will do to the body, what tissues most affected and pathways most affected. Answer in light of the big picture and reactions and pathways in other tissues/organs outside of the liver.  

Answer 1

1) Metabolic effects are liver failure

• Liver is the vital organ because it maintains homeostasis in the metabolism .
• It performs this function by mainatining carbohydrate metabolism , Fat metabolim , aminoacid metabolism and also performs hormonal regulation .
• In the case of liver failure , the above processes described gets impaired leading to overal metabolic stress .
• In the patients with cirrhosis , liver cannot function in response to glucagon, a hormone which maintains the blood glucose levels. Moreover these patients have defects in the glycogen breakdown . Glycogen is the source of glucose inthe periods of fasting . If the glycogen cannot be utilised then the patients would be hypoglycemic state.
• Lactate present in the foods are metabolised by liver . In liver failure patients , lactate concentration is high .
• Glycerol concentration also remiains high in the blood in liver failure patients.
• Moreover in general glucose production itself was less in these patients .Ultimately these patients have less energy .
• In lipid metabolism , the concentration of triglycerides was found to be high in cirrhosis, viral hepatitis and acute hepatitis . But it was lower than normal in hepatic carcinoma.
• Non -estrified fatty acids are also increased in liver disease. This itself impairs liver metabolism because non -estrified fatty acid decreases insulin secretion and results in elevated glucose concentration.
• Aminoacids in the protein are not effectively remove dfrom the body. The aminoacids are retained causing the levels of urea to be increased.
• In cirrhosis patients , glucose oxidation is also impaired in the presence of increase in peripheral fattyacid levels.
• Normally , galactose found in foods are assimilated by liver . In these liver failure patients, galactose and fructose assiilation cannot occur leading to accumulation of these substances.
• Insulin levels in the blood seems to be normal in certain patients but their response to glucose is less in peripheral tissues. In cirrhosis patients , the peripheral insulin levels are high. This is because , insulin doesnot bind to liver and thus liver cannot degrade insulin.
• Because of decreased insulin body tends to produce more of glucagon .
• Growth hormone and cortisol concentrations are also found to be increased in certain patients . This is because liver doesnot remove excess growth hormone in the blood.
• Thus , these are the metabolic effects of liver failure.

2)

• Liver failure causes impaired glucose secretion from glycogen . so glycogenolysis will be affected.
• Glycogenolysis , gluconeogenesis , glycogenesis are all affeted .
• Due to impaired fatty acid metabolism, lipoprotein synthesis is affected.
• Synthesis of components like cholestrol and phospholipids are also inhibited.
• Deamination and transamination of aminoacids , synthesis of glucose from non carbohydrate sources are also affected.
• Ammonia which is produced by metabolism is removed by hepatocytes and this process is impaired.
• Synthesis of Non -essential aminoacids, albumin , clotting factors are also impaired in the liver failure patients.
• Thus , these are the metabolic processes that are impaired due to liver failure.

3)

• Glucose , insulin , growth hormone , glucagon concentration varies which affects the overall metabolic effcets of the body.
• Due to decreased glucose concentration , body is deficient in energy needs .
• As insulin and glucagon concentration is fluctuating , it cannot maintain normal glucose levels .
• As aminoacid metabolism is impaired toxix substances like ammonia and urea gets accumulated leading severe metabolic disorders .
• Many auto immune diseases can be triggered in the case of liver failure patients .
• In cirrhosis patients the liver tissue itself gets affected and the liver is unable to function properly .
• Due to decreased glucose concentration over all tissues in the which needs glucose is affected . Mainly brain tissues are affected .
• Due to accumulation of urea and ammonia in the blood interupts all possible metabolic reactionjs of the body.

4)

• Liver disease affects digestive system . It causes gastro intestinal dysfunction . Bile cannot be excreted by the liver which directly affects the digestive system.
• Liver produces growth hormone .Inhibition of GH production causes impaired growth.
• RBC and WBCs count will be less due to liver failure.
• Autoimmune diseases can be triggered due to liver failure. Eg. Graves disease. one of the cause for this disease is diabetis . Diabetis is caused by impaired secretion of insulin. Thus liver also plays a major role in diabetis