physiology of lipid disorders SDL Flashcards
what change would be expected of insulin in a state of negative energy balance
decrease
what change would be expected of glucagon in a state of negative energy balance
increase
what change would be expected of growth hormone in a state of negative energy balance
Increases - Stimulates lipolysis to provide glucose for energy and stimulates tissue growth and repair. This preserves muscle mass and encourages the breakdown of adipose tissue for energy.
what change would be expected of cortisol in the state of a negative energy balance
Increases - promotes glycogenolysis and gluconeogenesis
what change would be expected of catecholamines in the state of a negative energy balance
Increase - promote glycogenolysis from liver, stimulate lipolysis, dilate airways, and constricts blood vessels.
what change would be expected of thyroxine in the state of negative energy balance
decrease - T4 has an energy conserving function which is not useful when there is a negative energy balance.
in ruminant physiology, which volatile fatty acids can be used to generate glucose or ketones
proprionate
what does hormone sensitive lipase do
Promotes the breakdown of triglycerides stored in adipocytes to glycerol and 3 fatty acids, in order to mobalise fatty acids. these released fatty acids can then be used as an energy store by various tissue in the body.
How is HSL inhibited and stimulated?
-Under normal conditions (positive energy balance) HSL is inhibited by insulin
-Other hormones eg. glucagon can reduce the inhibition by insulin
-Or other hormones can directly activate it eg. catecholamines, ACTH, cortisol, GH
-It is stimulated in negative energy states
triglycerides are released from adipocytes and cleaved to free fatty acids and glycerol. what is the consequence of too much FFAs for the liver to process for energy?
Excess fatty acids are converted back into triglycerides and stored in hepatocytes
triglycerides are released from adipocytes and cleaved to free fatty acids and glycerol. what is the consequence of too much acetyl CoA for availible oxaloacetate
Excess acetyl CoA is diverted into ketones (hydrophillic molecule containing a ketone group)
What clinical syndromes are to be expected in a periparturient cow with a negative energy balance and excessive lipid mobilisation
ketosis and fatty liver
What clinical syndromes are to be expected in a pregnant ewe with a negative energy balance and excessive lipid mobilisation
- ketosis
- fatty liver
- pregnancy toxaemia
What clinical syndromes are to be expected in an overweight pony with a negative energy balance and excessive lipid mobilisation?
- Hyperlipaemia
- Negative energy balance leads to mobilisation of fatty acids to provide source of energy.
- Overweight animals with a significant amount of stored fat may lead to an excessive amount of fatty acids released.
- this can overwhelm the liver, making it unable to process and export the excess fatty acids effectively.
- This leaves high levels of circulating fatty acids - hyperlipaemia.
- This can lead to an accumulation of fatty acids in the liver, which can lead to fatty acid disease.
What clinical syndromes are to be expected in an overweight cat with a negative energy balance and excessive lipid mobilisation?
- Hepatic lipidosis
- Lipids mobalised to make up for negative energy balance
- Overweight cat has a lot of stored fat so a lot of fatty acids are released into bloodstream.
- This overwhelms the liver which cannot process and export the fatty acids efficiently enough.
- Excess fatty acids are converted back to triglycerides and stored in hepatocytes.
- This leads to fatty infiltration, which can impair the livers normal function.
- As fat accumulates, hepatic lipidosis develops.
- This can lead to impair its ability for detoxification and synthesising essential proteins.
