Biochemistry

Question 1

Albumin

Answer 1

protein
made by liver
produced at constant rate
carries ion molecules - slightly negatively charged, attracts them

Question 2

globulin

Answer 2

protein
produced by liver and lymphocytes
liver - alpha and beta acute phase proteins
lymphopcytes - gamma - immunoglobulins

Question 3

hyperproteinemia

Answer 3

high albumin - dehydration
high globulin - dehydration, inflammation, neoplasia
lymphoma and myeloma produce monoclonal immunoglobulins - detection by serum electrophoresis
wide peak - wide variety of proteins making up the peak
thin peak - neoplasia

Question 4

hypoproteinemia

Answer 4

selective - drop in either globulin or albumin
panhypoproteinemia - both albumin and globulins low
most common
lymphoma, IBD, lymphangiectasia, parasites, severe burns

Question 5

Hypoalbuminemia

Answer 5

either not making enough albumin or losing too much
reduced production - liver disease, inflammation
losses - renal disease, effusion (movement from blood to body cavity)

Question 6

Hypoglobulinemia

Answer 6

rarer
usually also low albumin
dehydration may mask concurrent hypoalbuminemia
immunodeficiency - present from birth

Question 7

Panhypoproteinemia

Answer 7

both albumin and globulin low - most common type
protein losing enteropathy - common - lymphoma, IBD, lymphangiectasia, parasites
protein losing dermatopathy - rare - severe burns

Question 8

Liver and billiary enzymes (6)

Answer 8

SDH (large animals)
ALT (also muscles)
GLDH
AST (also muscles)
ALP
GGT (small increases significant)

Steroid ALP - elevated with Cushings, corticosteroids, or phenobarbitol
Bone ALP - increased with growth
smaller elevations more relevant in cats
Colostrum high GGT - used to check for passive transport

Question 9

Other hepatobiliary markers (6)

Answer 9

bile acids
bilirubin
cholesterol
albumin
glucose
coagulation factors

Question 10

bile acids

Answer 10

assessing liver function
produced by hepatocytes
bile acid stimulation test - sample when starved and after fed - increase in bile acids indicates reduced liver function (portosystemic shunt, cholestasis)

Question 11

bilirubin

Answer 11

conjugated (combines with glucuronide) vs unconjugated
from haem breakdown
increases -
- pre hepatic increase - excessive haem breakdown or inhibition of reuptake by hepatocytes - haemolysis, fasting
- hepatic increase - reduced ability to conjugate - toxins, lepto
- post hepatic increase - problem with bile from out to gut - gallstones, mucocoele, pancreatitis

Question 12

cholesterol

Answer 12

made by liver, taken up by lymphatics, released by adipose
present in bile
increases -
- cholestasis - also increased in bilirubin, GGT, ALP
- starvation - also triglyceride increase
- recent meal
- nephrotic syndrome

decreases -
- reduced intestinal absorption - GI disease, Addisons

Question 13

Coagulation factors

Answer 13

synthesised in liver
liver failure –> longer clotting times

Question 14

muscle enzymes (3)

Answer 14

CK - most muscle specific (short half life)
AST (long half lie)
ALT (more specific to liver than muscle)

Question 15

pancreatic enzymes

Answer 15

pancreatic lipase - diagnosis of pancreatitis
amylase - affected by GFR
TLI - used to diagnose exocrine pancreatic insufficiency

Question 16

sections of kidneys (functions)

Answer 16

glomerulus - electrolytes out
PCT - electrolytes in
loop of henle - descending loss of water, ascending electrolytes in
DCT and collecting ducts - water reabsorption for urine concentration

Question 17

Glomerular Filtration Rate (GFR)

Answer 17

increased in-flow - high CO, high BP
decreased in-flow - low CO, low BP

reduced flow through tubules - damage to nephron, UT obstruction
increased flow through tubules - diabetes, mannitol, diuretics, too much water, liver failure

Question 18

renal biomarkers (3)

Answer 18

urea
creatinine
SDMA

Question 19

Creatinine

Answer 19

made by muscles
excreted by kidneys
concentration dependant on production (muscle mass) and rate of excretion (GFR - kidney damage)

Question 20

urea

Answer 20

produced by liver
excreted by kidneys
concentration dependant on production (liver failure, increased with high protein diet and GI bleeding) and rate of excretion (GFR - kidney damage)

Question 21

SDMA

Answer 21

Released by all nucleated cells
excreted by kidneys
concentration depends on rate of excretion - GFR (only needs 35% nephron damage - more senstive)

greyhounds have naturally high sdma

Question 22

Azotemia

Answer 22

increased urea, creatinine, and/or SDMA

pre-renal - increase urea, problem with renal blood supply
renal - problem in kidney
post renal - obstruction of urine outflow

Question 23

Azotemia stages

Answer 23

1 - no azotemia - creatinine <1.4
2 - mild - 1.4-2.8
3 - moderate - 2.9-5
4 - severe - >5

Question 24

Acute kidney injury vs chronic kidney disease

Answer 24

how long signs for
collapse - acute
toxin ingestion - acute
skin lesions - acute
mild stage - more likely chronic
non-regenerative anemia - bad end stage kidney disease

Question 25

uraemia

Answer 25

build up or uremic acids (not secreting)
bradycardia, vomiting, respiratory distress

Question 26

major electrolytes

Answer 26

sodium - retained by kidneys to conserve water
chloride - moves with sodium
potassium - secreted in exchange for sodium

Question 27

sodium

Answer 27

most abundant electrolyte
maintains osmotic pressure
increases - free water loss (diabetes insipidus), water deprivation, salt poisoning, hyperaldosterone
decreases - severe diarrhoea or vomiting, renal failure, addisons, effusion, perspiration (horses)

Question 28

chloride

Answer 28

mostly copies sodium
sometimes lose more chloride than sodium - vomiting, pyloric outflow obstruction (loss of HCl from stomach)
lose more sodium than chloride - pancreatitis, fanconis syndrom (PCT defect), addisons

corrected chloride - to see if losing sodium and chloride in same proportions - work out how much is lost in relation to middle of reference interval

Question 29

potassium

Answer 29

regulates pH and cell electrochemical gradient
increases - acidosis, reduced renal excretion, artefact (hemolysis from samples being left out too long)
decreases - alkalosis, anorexia, perspiration (horses)

Question 30

acidosis

Answer 30

drop in blood pH

metabolic - build up in tissues - loss of sodium in excess to chloride, retained acids (ketones, lactate - tissue damage, uraemic acids)
respiratory - CO2 not expelled properly - neoplasia, obsruction, fibrosis, pneumonia

Question 31

alkalosis

Answer 31

increase in blood pH

metabolic - lost HCl - vomiting, twisted stomach, gastric foreign body, GI stasis
respiratory - tachypnoea (more CO2 out)

Question 32

mixed acid/base disorders

Answer 32

more than one concurrent issue:
renal failure + vomiting
diabetic ketacidosis + pancreatitis
vomiting causing asphyxiation pneumonia

Question 33

minor electrolytes (3)

Answer 33

calcium
phosphorus
magnesium

Question 34

calcium

Answer 34

total - bound + free/ionised

free calcium levels tightly controlled by PTH, vitamin D and calcitonin

excreted by kidneys and absorbed in intestine

Question 35

hypercalcemia causes (9)

Answer 35

hyperparathyroidism - decreased excretion
addisons - decreased excretion
renal disease - decreased excretion
D-hypervitaminosis - eg. rodenticide poisoning
idiopathic - common in cats
osteolytic - osteosarcoma
neoplastic - parathyroid
spurious - artefact, error
granulomatous disease - macrophages producing vitamin D

Question 36

hypocalcemia causes (7)

Answer 36

nutritional
renal
pregnancy/lactation
pancreatic pathology
toxins
tissue injury
rumen overload

Question 37

Phosphorus

Answer 37

increases - renal disease, release from injured cells (necrosis, rhabdo), excess vitamin D
decreases - increased excretion, fanconi’s, renal failure, reduced intake, hypovitaminosis D