A5: Evaluating Liver Function: Cholesterol Metabolism

What are the two main sources of cholesterol in the body? Where can smaller amounts of it come from (5)
1. Diet 2. Synthesis in the liver from Acetyl CoA 1. Adrenal glands 2. Sex glands 3. Intestine 4. Aorta 5. Skin
The rate of synthesis of cholesterol in the ____ is indirectly proportional to the amount that is what?
-liver -absorbed from the intestine
Cholesterol is carried in the bloodstream bound to a _______. Because lipids are insoluble in _____, in order to be transported in plasma they must be bound to a ______, and the resulting molecule is known as a _______
-protein -lipoprotein
What are the three types of plasma lipoproteins?
1. VLDL: Very low density lipoproteins 2. HDL: High density lipoproteins 3. LDL: Low density lipoproteins
The lipoprotein that is made up of 10% protein, 65% triglycerides, 25% cholesterol is the ________ it is aka the _____ lipoprotein which serves to do what? What kind of diet contributes to their production?
-VLDL -"Bad" -transport triglycerides to adipose tissue where they are then converted to arterial fatty plaque desposition -High fat diet
The lipoprotein which is made up of 50% protein, 37% triglycerides, 13% cholesterol is the _______ it is aka the _____ lipoprotein which serves to do what? What is a high level of this fat asscoiated with?
-HDL -"Good" -Transport cholesterol to the liver for elmination and helps prevent it from accumulating in the arteries -A lower risk of heart disease and fatty plaque formation
The lipoprotein which is made up of 25% protein, 20% triglycerides, 55% cholesterol is the ______ it is aka the _____ lipoprotein which serves to do what? What are the abnormal conditions?
-LDL -delivers cholesterol to body cells that need it, but in abnormal conditionsthey also deposit cholesterol in and around the smooth muscle fibers of the arteries. -when body cells have too few LDL receptors (genetics/environmental) so excessive LDL circulates
Rate the lipoproteins as the good, the bad and the ugly
1. Good: HDL 2. Bad: VLDL 3. Ugly: LDL
What is the substance that links carbohydrate, lipid and protein metabolism?
Acetyl CoA
What are the two methods commonly used in vet med to assess lipid metabolism?
1. Visually assess the blood sample for lipemia 2. Test the serum level of cholesterol
Hyperlipemia can result in visual changes in the blood sample causing it to have what kind of appearance?
cream of tomato soup
Lipemic serum or plasma has what kind of appearance?
whitish and opaque
What three laboratory tests can lipemia affect? Depending on what?
1. Blood glucose 2. Electrolytes 3. Plasma protein -Depending on the methods used
Lipemia enhances _______ which can contribute to altered test results
T o avoid lipemic blood samples what can we do?
Have the animal fasted 12 -24 hours prior to venipuncture because lipemia often occurs post prandial
Total serum cholesterol is measured by the ______ method
What is the most common cholesterol test in vet med? What can cause falsely high results and why?
Total serum cholesterol by the enzymatic method -Hemolysis, because cholesterol is present in all cell membranes
Name seven causes of hyperlipidemia
1. Postprandial 2. Idiopathic 3. Diabetes Mellitus 4. Hypothyroidism 5. Equine Hepatic Lipidosis Syndrome 6. Acute Pancreatitis 7. Hyperadrenocorticism (Cushings)
Lipemia normally occurs after _____ and may last up to ___ hours. It will typically clear after an ___ injection of ______
-eating -12 -IV -heparin
Idiopathic hyperlipidemia with __________ is diagnosed by ______ and occurs in what breed?
-hypertriglyceridemia -electrophoresis -Miniature Schnausers
Diabetes mellitus results in marked __________________ ( often with an increase or decrease in ________). Usually the ____ is a result of the increased _______
-hypertriglyceridemia -cholesterol -lipemia -lipolysis
Hypothyroidism results in a mild to marked lipemia with elevations in _______ and all _______
-cholesterol -lipoproteins
__________ results in a mild to marked lipemia with elevations in cholesterol and all lipoproteins
Equine Hepatic Lipidosis Syndrome results in a mild to marked ________________
T or F Feline Hepatic Lipidosis results in lipemia
__________ and elevated _______ levels can be involved in the the pathogenesis of and result of acute pancreatitis
-hyperlipidemia -cholesterol
Hyperlipidemia and elevated cholesterol levels can be involved in the _____________ and be the result of _______ ________
-pathogenesis -acute pancreatitis
In hyperadrenocorticism both exogenous and endogenous ________ can result in hyper______ due to increased _______
-corticosteroids -hyperlipemia -lipolysis
In _____________ both exogenous and endogenous corticosteroids can result in hyperlipemia due to ______ ______
-hyperadrenocorticism -increased lipolysis
T or F Hypercholesterolemia is a definitive sign of various disease processes
F Not a definitive sign of any disease
Hypocholestrolemia is used in conjunction with other diagnostic tests to support a diagnosis with the following six diseases:
1. Hypothyroidism 2. Hyperadrenocorticism 3. Diabtetes Mellitus (cholesterol can increase or decrease) 4. Nephrotic syndrome 5. Obstructive biliary disease 6. Early stage Acute Renal Failure
T or F Hypolipidemia is rare
Hypolipidemia _____ occurs, but ________ deficiencies occur and are are usually _____ in origin
-rarely -lipoprotein -genetic
Name three diseases hypocholesterolemia can occur in
1. Hepatic disease (reduced cholesterol production) 2. Diabetes Mellitus (cholesterol can increase or decrease) 3. Malnutrition/anorexia (due to decreased production)
What can happen to cholesterol levels in diabetes melitus?
They can either increase or decrease
When excessive lipolysis occurs and more ketones are produced than can be utilized what is this called?