Lipids And Ketones Flashcards
What is the main function of lipids in veterinary species?
- Energy Source
- structural components of cell membranes
- substrates for hormones and chemical messengers
What are the most commonly measured ketones?
BHB (b-hydroxybutyrate)
How do lipids most commonly travel around the blood?
Blood complexed with proteins (lipoproteins)
What is lipaemia in blood samples usually due to?
Triglycerides rather than cholesterol
What three things can cause lipid metabolism disorders?
- Excess synthesis
- Defective lipolysis
- Defective clearance or uptake of lipoproteins
Where are lipoproteins produced?
small intestinal enterocytes and hepatocytes
Where does the lipolysis of lipoproteins occur?
on the luminal surface of the capillary endothelial cells
What catalyses the lipolysis of liporoteins?
lipoprotein lipase
What clears the lipoprotein remnants from the plasma
hepatocytes
Where is the cholesterol mostly contained in a fasting sample?
Contained within lipoproteins
Where is the majority of cholesterol produced?
In the liver beginning with acetyl-CoA
What is hypercholesteraemia?
Increased Cholesterol Production
may be due to hypoadrenocorticism
What can cause both hypercholesteraemia and Hypertrygliceridaemia?
- Decreased Lipolysis or intravascular processing of lipids
- Diabetes mellitus
- Increased Cholesterol or Triglyceride production
What is hyperlipaemia syndrome secondary to?
Can be secondary to anorexia, obesity, pregancy, lactation, renal failure
What can cause hyperlipaemia?
the mobilisation of fatty acids from TG molecules of adipose tissue
What can severe hyperlipaemia then cause?
TG accumulation in the hepatocytes which then goes on to cause hepatic lipidosis and liver damage
What do NEFA’s form from?
hydrolysed triacylglycerol in the adipose tissue, liver and mammary gland
What is hydrolysis in adipocytes mediated by?
hormone sensitive lipase
Where does ketogenesis occur?
It occurs in hepatocytes, transforming acetyl coA into beta hydroxybutyrate, acetoacetate and acetone
When may ketosis occur?
excessive beta oxidation of fatty acids which leads to more acetyl-CoA than can be metabolised by the krebs cycle
Why is cholesterol esterified?
Free cholesterol can be toxic to the body
What delivers cholesterol?
generally LDL delivers cholesterol from the liver to other cells in the body
What do NEFAs form after Beta oxidation?
acetyl-coA
acetyl coa is used for the generation of energy
What does increased NEFA’s mean?
more fat mobilisation in response to a negative energy balance
What can cause ketonaemia?
Starvation, prolonged anorexia, diabetes mellitus
