Proteins Flashcards
What organ synthesises the majority of proteins?
The majority are synthesised within the liver
Where are the majority of immunoglobins synthesised?
within the lymphocytes, particuarly B lymphocytes
What is panhypoproteinaemia
loss of all proteins/fractions
What is selective hypoproteinaemia?
Loss of specific proteins
What is Hyperproteinaemia?
High Blood Protein
Can be selective or non-selective
What is plasma?
anticoagulated blood
What is the serum?
The supernatant on top of the plasma
does not contain clotting factors
What is protein dyscrasia?
abnormal proteins
What is a colourimetric assay?
Using a colourimeter to determine the chemical concentration of a compound in solution by measuring the absorbance
What is a turbidometric assay?
Particle bound antibodies are mixed with the assay
The level of light transmitted reflects the amount of antigen in the solution
What are the three different types of electrophoresis?
- Agarose gel
- Cellulose acetate gel
- Capillary zone electrophoresis
What is the most common individual protein in blood
albumin
In what type of animal is pre-albumin seen prominently?
in exotics
In what organ is albumin produced?
The liver
What is albumin predominantly responsible for?
For maintaining colloidal osmotic pressure
Binding cationic substances such as ca2+ and Mg2+
What are the two most common tests used to measure albumin?
Bromocrescol purple and Bromocrescol green
What is the issue with Bromocrescol green and exotic species?
It is not generally optimal for exotic species
How would you calculate globulin on a chemistry profile?
Total protein- albumin
What factor causes proteins to migrate to the left during electrophoresis?
Charge and weight
What is the most common cause of hyperproteinaemia?
Haemoconcentration (increase in the number of Red Blood Cells relative to the plasma)
What is non-selective hyperproteinaemia?
All fractions increase equally
What peak is albumin expected to be during protein electrophoresis?
It is generally the peak to the left and expected to be the tallest and narrowest at the base
What does monoclonal expansion look like?
The protein peak has a base width similiar to albumin
What does polyclonal expansion look like?
The base of the peak is broad, it reflects the expansion of multiple different proteins in the face of inflammation
What are acute phase proteins?
Proteins that alter in response to inflammatory stimulus
What is a positive acute phase protein?
Where the levels increase in response to inflammation
What is a negative acute phase protein?
Levels decrease in response to inflammation
What is a major acute phase protein?
Levels change by 100-1000 fold, they usually peak 24-48 hours after insult and then rapidly decline
What is a moderate acute phase protein?
Increases 5-10 fold in response to inflammation, peaks around 48-72 hours, declines are slower than most APP’s
What is a minor acute phase protein?
Increases 50-100% above resting levels, increases are gradual
What is the function of C-Reactive Protein?
major positive APP in dogs
On bacteria it promotes the binding of complement, facilitating phagocytosis
It inhibits chemotaxis and modulation of neutrophil function
What can C-Reactive Protein be used to monitor?
Long term monitoring of refractory cases
What is Serum Amyloid A?
Major APP in the horse, often used for monitoring and assessing for inflammation
* chemotactic recruitment of inflammatory cells to sites of inflammation
What two things lead to HypoProteinaemia?
- Increased Loss of Proteins
- Decreased Production of Proteins
What can cause increased Loss of Proteins?
- Panhypoproteinaemia/ selective albumin loss
- Blood loss (external haemorrage)
- Protein losing nephropathy
- Protein losing enteropathy
- Protein losing dermatrophy
Name 4 things that can lead to decreased Protein production
- Hepatic insufficency
- Malabsorption/ Maldigestion
- Cachetic states
- Lymphoid hypoplasia/ aplasia
What is another name for an antibody?
an immunoglobulin
What are the three different types of protein?
- alpha
- beta
- gamma
What are some examples of alpha proteins?
a1- lipoprotein
a1- antitrypsin
a1- antichymotrypsin
a2- macroglobulin
What are some examples of beta proteins?
B1- haptoglobin
B1- Transferrin
B2- lipoproteins
B2 Complement C3a
B2 IgM and IgA
What are some examples of gamma proteins?
igG
C-Reactive Protein
What is a monoclonal expansion of globulin, shown by an increase in a narrow peak on the right most likely to be?
neoplasia
What is the definition of an acute phase protein?
Protein where the levels either increase or decrease due to inflammation
What is the issue with using bromocrescol purple to measure albumin?
can give false low levels in dogs
What is the most common cause of hyperproteinaemia?
haemoconcentration (loss of plasma H2O)
What would the protein electrophoresis peak look like during monoclonal expansion?
Usually in the gamma region (far right)
Same width as albumin
What does the polyclonal expansion peak look like in proetin electrophoresis?
Base of the peak is broad
examples include FIP in cats
Give four examples of positive acute phase proteins
- C-reactive
- Serum amyloid
- Haptoglobin
- Fribrinogen
Give two examples of negative acute phase proteins
- albumin
- transferrin
What is alpha one acid glycoprotein?
- antiinflammatory and immunomodulatory agent
- binds to liphophillic and acidic drugs
- levels are associated with FIP
What is haptoglobin?
- Binds free haemoglobin
- Natural antagonist for receptor-ligand activation
- Often used in cattle
What is the challenge when proteins are increased and there is a possibility of dehydration?
can be challenging to assess if
there may be increase in proteins due to haemoconcentration or due to increased production in
response to inflammatory demand
What are some ways proteins can be lost?
- panhypoproteinaemia (selective blood loss)
- protein-losing nephropathy
- Protein-losing enteropathy
- Protein-losing dermatopathy (e.g burns)
What causes decreased production of proteins?
- Hepatic insufficiency ( albumin is the most affected)
- malabsorption or maldigestion
- cachetic state
What is failure of passive transfer?
inadequate amounts of immunoglobulin are aborsbed prior to gut closure leaving the neonate susceptible to disease
