Lab D 6 Metabolic parameters; lipids Flashcards
Presence of lipaemia, analysis method
- To differentiate chylomicrons (after a meal) from other lipids in blood plasma.
- Freeze plasma (-18C), wait 12-24h, warm up slowly, centrifuge -> protein part of chylomicrons coagulate
- If the layer under the fat (which is located on top of the plasma) is clear: lipaemia caused by food intake, in this case plasma is ready for measurement
Presence of lipaemia, analysis method;
If the layer under the fat (which is located on top of the plasma) is clear:
Lipaemia caused by food intake, in this case plasma is ready for measurement
Presence of lipaemia, analysis method; If the layer under the fat (which is located on top of the plasma) is not clear:
It means that there is an increased lipid mobilization from the fat stores
Causes of hyperlipidaemia
- Hyperlipidaemia in ponies
- Increased fat content in diet
- Diabetes mellitus (decreased FFA, influx into the cells)
- Hypothyroidism
- Hyperadrenocorticism or glucocorticosteroid therapy
- Nephrotic syndrome
- Septicaemia (energy deficiency)
- Pancreatitis (lipase activation)
- Idiopathic - familiar hyperlipidaemia in miniature schnauzers, beagles
Causes of decreased lipid content
- Starvation (long term)
- Liver failure (ex. portosystemic shunt - PSS)
- Malabsorption, maldigestion (ex. exocrine pancreaticinsufficiency - EPI)
Lipid absorption test, why do we perform this test
- To determine whether there is malabsorption, maldigestion or chronic bowel disease
Lipid absorption test, normal response
- When there is fast lipid intake in normal conditions, plasma triglycerol concentrations rises to twice the normal value
When there is fast lipid intake in normal conditions, plasma triglycerol concentrations rises to twice the normal value , what is the normal value for dogs?
1mmol/L
Lipid absorption test, method
- Animal starved for 24h
- Blood sampling, then 3ml/kg bw corn oil is given orally, blood sampling at 1st, 2nd, 3rd, 4th, 5th hours after administration, blood should be lipaemic and triglycerol conc must show minimal 2fold rise from normal value
- If no change: have to repeat test by giving predigesten corn oil. Predigested by pancreatic enszyme extract mixed in corn oil and incubated at 37C -> give same dose and check lipaemia every hour
- -> If then the result is increased value of triglycerides, we can suspect exocrine pancreatic insufficiency. If still no change, we can suspect intestinal absorption defect
Lipid absorption test, method - if no change in triglyceride value we can suspect
If no change: have to repeat test by giving predigesten corn oil. Predigested by pancreatic enszyme extract mixed in corn oil and incubated at 37C -> give same dose and check lipaemia every hour
–> If then the result is increased value of triglycerides, we can suspect exocrine pancreatic insufficiency.
Lipid absorption test, method - if no change in triglyceride value even after giving predigested corn oil we can suspect
If still no change, we can suspect intestinal absorption defect
Total cholesterol and cholesterol-ester, detecting what?
We use cholesterol measurements for detection of increased fat mobilization - in this case the total cholesterol value increases and cholesterol catabolism decreases
Important: how much (%) of the total cholesterol value is the cholesterol-ester?
Cholesterol-ester is 40% of the total cholesterol value
Decreased esterification of cholesterol as a result of impaired liver-function and decreased apolipoprotein production, causes decreased?
Total cholesterol concentration
Causes of hypocholesterolaemia
- Malnutrition
- Liver failure (decreased synthesis)
- Neoplastic disease
- Hyperthyreosis (increased use)
- Decreased apolipoprotein synthesis
