4. Metabolic parameters Flashcards
What is the total protein content of the plasma (serum) is dependent on?
Intake, synthesis, transformation, catabolism, and hydration status (dehydration, hyperhydration)
How can we measure TP?
Biuret method, chromatography, electrophoresis and refractometry.
What is the best detection range of the Biuret method/refractometry?
20-100 g/l
What is the average TP concentration of plasma?
60-80 g/l
How can be determine smaller TP concentrations?
- Lowry method: Folin-phenol reagent
- Ultrasensitive TP method
Biuret test
- Type of test?
- Reagent contains?
- Schematic chemical reaction?
- Wave length?
- Detects presence of peptide bonds.
- KNaSCN, CuSO4, KI and NaOH.
- CO-NH+ Cu2++ alkaline = purple coloured complex
- 546 nm
Ultrasensitive total protein analysis
- Reagents?
- Wave length?
- Sensitivity?
- Standards?
- Na-molibdate, and pirogallol-red reagent forms a complex molecule by binding proteins.
- 600 nm
- 0.2 g/l - 4g/l.
- 0.25, 0.5, 1. 2 g/l.
Refractometry - Which range can it be used?
25-95 g/l
What happens with TP during dehydration and hyperhydration?
During dehydration TP increases, or hyperhydration TP decreases.
Major fractions of protein
Albumin, globulin and fibrinogen. Fibrinogen is in the smallest quantity.
Plasma TP in…
- Dog
- Cat
- Horse
- Cattle
- Swine
- Sheep
- Dog: 67-70
- Cat: 70-75
- Horse: 68-70
- Cattle: 75-85
- Swine: 65-77
- Sheep: 58-60
g/l
Serum albumin in…
- Dog
- Cat
- Horse
- Cattle
- Swine
- Sheep
- Dog: 25-34 48-64%
- Cat: 25-45 43-63%
- Horse: 27-40 40-60%
- Cattle: 23-40 35-55%
- Swine: 27-39 40-62%
- Sheep: 24-30 50-60%
Serum globulin in…
- Dog
- Cat
- Horse
- Cattle
- Swine
- Sheep
- Dog: 30-48 11-21%
- Cat: 30-48 8-24%
- Horse: 40-62 15-20%
- Cattle: 30-55 12-17%
- Swine: 30-65 12-25%
- Sheep: 30-58 11-16%
Albumin/Globulin in…
- Dog
- Cat
- Horse
- Cattle
- Swine
- Sheep
- Dog: 1,083
- Cat: 1,083
- Horse: 0,61
- Cattle: 0,81
- Swine: 0,54
- Sheep: 0,724
Fibrinogen in…
- Dog
- Cat
- Horse
- Cattle
- Swine
- Sheep
- Dog: 1-4
- Cat: 1-4
- Horse: 2-4
- Cattle: 2-5
- Swine: 2-4
- Sheep: 2-4
Albumin conc. measurement methods
- Spectrophotometry. Reagent: Bromocresol green. It binds to albumin on pH 4.2 and forms a blue-green complex which is measurable on 578 nm wave length.
- Serum electrophoresis, in combination with TP measurement
Changes of albumin concentration
Decrease:
-Decr. intake of proteins, decr. absorption
-Decr. synthesis - liver failure, acute inflammation
-Incr. utilisation
-Incr loss: via the kidneys, gastrointestinal tract, skin (burn), whole blood loss, sequestration into body cavities
-Other: hyperhydration
Increase: dehydration
Globulins conc. measurement methods
- Method 1: Calculation: by difference of TP and albumin conc of serum.
- Method 2: Serum electrophoresis
Causes of decrease of albumin/globulin ratio
- Incr of globulin conc. e.g inflammatory processes or processes related to neoplasia.
- Decrease of albumin conc.
Electrophoresis
- Based on?
- How does it work?
- What is it separated into?
- Which molecules will move furthest?
- That proteins have amphoteric character
- Blood serum is placed on paper w. agarose gel and exposed to an electric current to sep. the serum protein components into five classifications by size and electrical charge
- Serum albumin, alpha-1-globulins, alpha-2-globulins, beta globulins, and gamma globulins.
- Small and highly charged molecules
Electrophoresis
- What is it based on?
- Medium?
- How is it separated?
- Which molecules move furthest?
- the fact that the proteins have amphoteric character (acidic amino acids - Asp, Glu) go to the + pole (charge) alkaline amino acids go to the - pole.
- paper treated with agarose gel
- into five classifications by size and electrical charge; albumin, alpha-1-globulins, alpha-2-globulins, beta globulins, and gamma globulins
- small and highly charged molecules
Serum protein electrophoresis (SPEP)
is a laboratory test that examines specific proteins in the blood called globulins.
gel electrophoresis
the medium is typically polyacrylamide or agarose, a viscous media that is required to minimize diffusion of the constituent ions.
Serum protein electrophoresis (SPEP)
Examines specific proteins in the blood called globulins.
Medium of gel electrophoresis
Typically polyacrylamide or agarose
The two most commonly used forms of protein electrophoresis are?
- Sodium docecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)
- Isoelectric focusing (IEF)
ISDS-PAGE
- Which proteins will move furthest?
- Which proteins will move through the gel matrix at a slower rate?
- Which proteins will move closer to the anode?
- Larger denatured proteins
- Larger denatured proteins
- The smaller proteins
How can we distribute plasma protein fractions by their electrophoretic character?
Albumin, alpha-1, alpha-2, beta-1, beta-2, gamma-1, gamma-2.
- Alpha-globulins are acute phase proteins
- Beta-globulins are imunoglobulins (IgA, IgM)
- Some other proteteins i.e. LDL, gamma-globulins are immunglobulins (IgG).
- What does serum contain?
2. What does plasma contain?
- 60% of albumin, 40 % of globulin
2. 50% of albumin, 30% of globulin, 20% of fibrinogen
Where does immunoglobulins derive from?
Special lymphoid cells (plasma cells)
What is polyclonal and monoclonal gammopathy?
- Polyclonal gammopathy: Beta and gamma globulins derived from different clones.
- Monoclonal gammopathy: one protein fraction derived from one clone
Polyclonal gammopathy
- How is it seen?
- Common causes
- As a broad-based peak in the beta and/or gamma region.
- Generally inflammatory processes or some immune mediated diseases. Various chronic inflam. diseases, liver disease, FIP, occult heartworm disease, and Ehrlichiosis.
Monclonal gammopathy
- How is it seen?
- Common causes
- As a sharp spike in the beta or gamma region. Like albumin.
- Immune mediated or neoplastic conditions. Both neoplastic and non-neoplastic disorders.
Causes of neoplasia
- Most common: Multiple myeloma
- Other-associated with monoclonal gammopathy: lymphoma (IgM or IgG) and chronic lymphocytic leukemia (usually IgG).
Extramedullary plasmacytomas
Solid tumors composed of plasma cells that are usually found in the skin of dogs.
- They have also been reported in the GI-tract and liver of cats and dogs.
- They can be associated with a monoclonal gammopathy, or even a biclonal gammopathy (if there are multiple tumors).
What is an increase in IgM called?
Macroglobulinemia
Waldenstrom’s macroglobulinemia
A neoplasm of B-cells (lymphoma) that has a different presentation from multiple myeloma.
-Patients usually have splenomegaly and/or hepatomegaly and lack osteolytic lesions.
Non-neoplastic disorders
-Rare.
-Monoclonal gammopathies (usually IgG) have been
reported with occult heartworm disease, FIPV (rarely), Ehrlichia canis, lymphoplasmacytic enteritis, lymphoplasmacytic dermatitis and amyloidosis.
-These causes should be ruled out before a diagnosis of multiple myeloma is made in a patient with an IgG monoclonal gammopathy.
Hypoglobulinaemia
- decr intake of globulins: in neonates before drinking colostrum, absorption disorders of neonates
- decr synthesis of globulins: acquired of inherited immunodeficiency, liver function impairment
- incr loss: PLE, PLN, via skin (burns, inflammation), bleeding
Fibrinogen concentration - methods
- Calculation (difference of plasma and serum TP-conc)
- Heat labile character of fibrinogen
- Thrombin time (TT)
Cause of increase of fibrinogen conc
Acute inflammation (especially ruminants), dehydration
Cause of decrease of fibrinogen conc
- Liver function impairment
- advanced protein deficiency
- DIC
- sequestration after bleeding to body cavity
- chronic bleeding
- blood loss
- inherited afibrionogenaemia (St. Bernard dog)
Glucose measurement
- Glucometer
- GOD/POD
Blood used for glucose measurement?
Plasma
How to avoid in vitro glucose catabolism?
- Store sample cooled until measurement
- Separate plasma from blood quickly
- Coagulate RBC by i.e. 3% trichloric acetic acid
- Take blood samples in tubes containing NaF
Causes of glucose increase
Transient increase: o laboratory errors o stress o food intake o xylazin effect o cranial trauma or inflam o after/during administration of glucose containing fluid therapy Constant hyperglycaemia o diabetes mellitus o hyperadrenocorticism and glucocorticosteroid therapy o Progesterone effect o enterotoxaemia
Causes of decreased glucose conc
laboratory error decreased energy status insulin overdose insulinoma anabolic steroid effect liver failure, terminal stage acute liver failure hypoadrenocorticism septicaemia hyperthyroidism paraneoplastic syndrome
When do we use Intravenous glucose tolerance test?
When we suspect the onset of latent diabetes mellitus or insulinoma
When do we use Oral glucose tolerance test (glucose absorption test) ?
When we suspect chronic bowel disease, exocrine pancreatic insufficiency, or can be used instead of iv glucose tolerance test.
Macroamylase
When glucose is bound to alpha-amylase the size of the complex molecule is bigger
Causes of keton bodies
Energy deficiency in liver cells: can be caused by decreased intake of carbohydrates or decreased insulin production (diabetes ketoacidosis)
Ross-reagent?
- When do we use Ross-reagent?
- Colour change?
- Samples used?
- Estimation of concentration of acetone, and acetoacetic acid. Detection of keton bodies.
- White/grey -> purple
- Milk, urine, plasma
How do me estimate the Energy status of cattle (dairy cows)?
Urea concentration analysis from milk and plasma.
Causes of hyperlipidaemia
hyperlipidaemia of ponies
increased fat content in diet
diabetes mellitus (decreased free fatty acid /FFA/ influx into the cells)
hypothyroidism
hyperadrenocorticism or glucocorticosteroid therapy
nephrotic syndrome
sepitcaemia (energy deficiency)
pancreatitis (lipase activation)
idiopathic – familiar hyperlipidaemia in miniature schnauzers, beagles
Causes of decreased lipid content
starvation
liver failure
malabsorptio, maldigestio
When do we use Lipid absorption test?
To determine whether there is existing malabsorption, maldigestion or when there is chronic bowel disease we perform this test
Why do we measure Cholesterol?
Detection of increased fat mobilisation
The cholesterol-ester in total cholesterol value?
The cholesterol-ester is 40% of the total cholesterol value.
Causes of decreased esterification of cholesterol as a result of impaired liver-function
Decreased total cholesterol concentration.
Average normal value for cholesterol conc
2-6 mmol/l
Causes of hypocholesterolaemia
malnutrition liver failure (decreased synthesis) neoplastic disease hyperthyreosis (increased usage) decreased apolipoprotein synthesis
Causes of hypercholesterolaemia
increased dietary fat content hypothyroidism hyperadrenocorticism diabetes mellitus nephrotic syndrome cholestatic diseases idiopathic - primary dyslipidosis
When do we use FFA or NEFA (non-esterised-fatty-acid) conc measurement
Detect increased or decreased lipid mobilisation
Average normal values:
- free fatty acid, FFA
- total lipid, TL
- triacyglycerol, TG
- cholesterol, Chol
- FFA: 0,1-0,3 mmol/l
- TL: 5-7 mmol/l
- TG: 0,6-1,2 mmol/l (sheep: 1,5-4 mmol/l)
- Chol: 2-6 mmol/l
What is the apolipoproteins of these lipid fractions :
- triacil-glycerols
- phospholipids
- cholesterol
- cholesterol-ester
- free fatty acid
- triacil-glycerols - VLDL
- phospholipids - HDL
- cholesterol - LDL/HDL
- cholesterol-ester - (HDL)
- free fatty acid - albumin