Kerry Loomes 6 Flashcards
What are the features that characterise diabetes?
High blood sugar caused by a lack of insulin or lack of insulin action, polyuria, polydipsia, weight loss, blurred vision
What type of hormone is insulin?
An anabolic hormone, consequently the body will enter a catabolic state in its absence, acting as though it is in the starved state despite the fact there is actually an excess of glucose in the blood
What happens to the liver in type 1 diabetes?
The liver is unable to shut down glucogenesis and glycogenolysis and additional glucose is released into the bloodstream
What happens to adipocytes in type 1 diabetes?
Adipocytes leak fatty acids into the blood as insulin is needed for glucose entry
What happens to skeletal muscle in type 1 diabetes?
It unable to take in glucose or amino acids effectively
What occurs to the pancreas in type 1 diabetes?
The insulin producing alpha islet cells are destroyed leading to an inbalance of insulin secreting and glucagon secreting cells effectively reducing insulin concentrations to no therapeutic benefit
Why is there an inability of fat cells to store glucose efficiently in type 1 diabetes?
Glucose cannot enter the cell so the free fatty acids from VLDLs cannot efficiently be taken up by the cell as glycerol-3P which forms the backbone of the triacylglyceride molecule is not present leading to inefficient storage
Hormone sensitive lipase is also no longer inhibited resulting in lipolysis occurring
What happens to liver metabolism in type 1 diabetes?
The dramatic loss of glucose caused by the liver remaining in the catabolic state results in the liver needing to try to produce glucose to supply the brain even though its supplies are depleted, this is done through the production of ketone bodies which compensates for a lack of glycogen stores
What occurs to metabolism in skeletal muscle in type 1 diabetes?
Muscle breakdown occurs due to the inability of the muscle to take up amino acids or glucose to produce glycogen stores
In the starved state muscle plays a key role in maintaining glucose levels by being broken down and exported as amino acids alanine (to made into glucose and pyruvate in the liver) and glutamine is used as fuel by the intestines and kidneys
How are the ketone bodies seen in type 1 diabetes formed?
Acetyl coA is formed from pyruvate and fatty oxidation
Acetyl coA enters the krebs cycle through condensing with oxaloacetate
If there is more acetyl coA than can enter the krebs cycle through this process then the formation of ketone bodies increases with acetone being formed from a spontaneous decarboxylation of acetoacetate
What is the benefit of producing ketone bodies in the starved state?
The brain needs to be supplied energy in the form of glucose, free fatty acids cannot be used as they cannot be used to synthesis glucose.
Ketone bodies are able to convert fatty acids into a form of usable energy by the brain which can help prevent muscle breakdown
What is ketosis?
Elevated levels of ketone bodies in the blood through lipolysis and beta-oxidation. Can be caused by fasting
What is ketoacidosis?
High concentrations of ketone bodies causing blood to drop below pH 7.2 can be fatal
