Lecture 2 Flashcards
(42 cards)
What are plasma proteins made of?
Albumin
Globulins
Fibrinogen
Where are proteins made?
Liver- most plasma proteins
Lymphoid organs- immunoglobulins
Protein functions
Colloid osmotic pressure
Acid-base buffering
Hemostasis- coag factors
Inflammatory regulators
Immune defense
Molecular transport
Nutritive
Cellular structure
Enzymatic catalysts
Hormones
What is the major colloidal particle contributing to colloid osmotic pressure
Albumin
What does decreased COP (hypoalbyminemia) cause?
Fluid to accumulate outside the vascular space forming edema/effusion
How are proteins removed
Catabolism
GI loss- protein losing enteropathy
Renal loss- protein losing nephropathy
How are proteins replaced
Dietary intake
Synthesis
What does the protein half-life depend on?
Species and body size
What are three ways to measure protein?
Physical- refractometer
Biochemical- spectrophotometry
Fractionation- electrophoresis
Refractometry
Based on fluids refractive index
Quick screen of total proteins
Affected by other solutes in solution- lipemia, hemoglobinemia, hyperbilirubinemia, other things (Na, Cl, glucose, etc.)
Fibrinogen estimate
Uses a refractometer and heat precipitation
When does fibrinogen increase? Decrease?
Increases with active inflammation and physiologic stress
Decreases with DIC, snake bites, and liver failure
Describe colorimetric biochemical protein measurements
Color changes correlate with protein content
Artifact- albumin will be higher in heparinized plasma than serum
Describe turbidimetric biochemical measurement of protein
Adds a reagent that causes the proteins to precipitate
Results in cloudiness that corresponds to amount of protein
Used in urinalysis and CSF samples
Serum protein electrophoresis
Performed when unexplained hyperglobulinemia is present (i.e. cannot be attributed to hemoconcentration) or when an immunoglobulin deficiency is suspectied
What are some things that affect protein concentration?
Age, diet, hormones, fluid balance, disease states
How do proteins differ based on age?
Neonates have very albumin and no globulin (before ingestion and absorption of colostrum)
Old patients may have lower plasma proteins
How might the diet affect plasma proteins?
Hypoalbuminemia may occur when protein intake does not meet protein needs (increased physiologic demands, decreased intake, decreased absorption)
How might fluid balance affect protein concentrations?
Dehydration= causes relative hyperproteinemia
External hemmorhage= causes hypoproteinemia and anemia because fluid is replaced faster than cells
How might disease states affect protein concentrations?
Inflammation can cause increased loss of proteins (increased vascular permeability or increased tissue catabolism)
Inflammation can also cause increased synthesis of positive APP and decreased synthesis of negative APP
Acute phase proteins
Increase or decrease their concentration in response to inflammatory cytokines
Protects host- hemostasis, conserve nutrients (keep away from infectious agents), and immunomodulation
Which globulins are most APPs?
Which immune system are they part of?
Alpha and beta globulins
APPs are part of innate immune system
Increased production of APPs is an indicator of what?
Inflammation! Can be detected prior to inflammatory leukogram
What are three important positive AAPs?
C-reactive protein
Serum amyloid A
Fibrinogen
