Biochemistry

Question 1

What are some roles of the liver?

Answer 1

• Synthesis (glucose, bile acids for fat absorption, clotting factors, ketone bodies, albumin)
• Inflammation (globulins)
• Detoxification and excretion of waste products (bilirubin, ammonia, Cu, drugs/poisons)
• Storage (lipid, carbs, vit ADEK, Fe)
• Fe metabolism

Question 2

What are the signs of liver disease?

Answer 2

• Depression, inappetence, stunting
• Jaundice *
• Vomiting, diarrhea, PU/PD
• Ascites (fluid build up in abdomen)
• Hepatomegaly (abnormal enlargement of liver)
• Coagulopathy (clotting impaired), encephalopathy (damage/disease that affects the brain)

Question 3

What is albumin?

Answer 3

A protein made by the liver. It’s function is to keep fluid in your bloodstream so that it doesn’t leak into other tissues.

Question 4

What are some typical plasma changes seen with hepatic injury?

Answer 4

• Inc. in hepatic and biliary enzymes
• Dec. in albumin with Inc. in y-globulins/other globulins
• Inc. in bilirubin and bile acids

Question 5

What is the ALT (alanine transaminase) and GLD (glutamate dehydrogenase) function in amino acid metabolism?

Answer 5

• NH3 from muscle breakdown
• ALT traps it as alanine
• Alanine taken to liver
• ALT traps NH3 as glutamate
• GLD releases NH3 into urea cycle
• NH3 trapped as urea

Question 6

What is ALP?

Answer 6

Alkaline phosphatase.

• Standard biomarker for cholestasis (liver disease)
• In liver cell membrane (on side of bile cuniculi)
• Transports things across the membrane
• Inc. in young animals to make bone
• Steroid induced in dogs

Question 7

What is prehepatic jaundice?

Answer 7

Increased bilirubin production in hemolysis or internal haemorrage.

Question 8

What is hepatic jaundice?

Answer 8

Liver fails to take up bilirubin from blood or conjugate it, in liver disease.

Question 9

What is post-hepatic jaundice?

Answer 9

Obstruction of bile flow - pancreatic necrosis, bile duct tumors or inflammation.

Question 10

What is intracellular fluid mainly made up of?

Answer 10

K+, Mg2+, organic phosphate & protein

Question 11

What is extracellular fluid mainly made up of?

Answer 11

NaCl, HCO3- (bicarbonate)

Plasma is similar to ECF but has higher protein.

Question 12

How is the measurement of electrolytes done? When does electrolyte imbalance usually occur?

Answer 12

-Collection tubes must be clean and dry
-2ml blood, clotted or heparinised are fine
-Haemolysis to be avoided, as RBC & plasma electrolytes differ
Electrolyte imbalance usually occur as a result of fluid imbalance with vomiting and diarrhea, also with renal disease, adrenal disease & gut obstruction

Question 13

What does a) an increase in NaCl indicate and b) a decrease in NaCl indicate?

Answer 13

A) Dehydration, excess salt intake, water restriction (Cushing’s disease & urinary tract obstruction)
B) Chronic renal failure, prolonged vomiting/diarrhea, water intoxication (high gut obstruction, metabolic acidosis)

Question 14

What does a) an increase in K indicate and b) a decrease in K indicate?

Answer 14

A) Renal failure, Addison’s disease, acidosis, shock/circulatory failure
B) Prolonged vomiting and diarrhea, metabolic alkalosis

Question 15

What are the signs of acute pancreatitis(inflammation)/pancreatic necrosis?
How would you test for these?

Answer 15

-Anorexia, lethargy, colic in dogs/cats, colic in horses
-Tests: Amylase (digests carbs) -poor
Non specific lipase (breakdown lipid) -poor
Pancreatic lipase -good
TLI -poor

Question 16

What are the functions of the pancreas?

Answer 16

Exo:
-Release enzymes into intestine to help break down food (Trypsin is one). Enzyme for protein, for carbs etc.
-Produce neutralizing substance to help neutralize HCL in stomach
Endo:
-Hormones i.e. insulin

Question 17

What is pancreatic trypsin -TLI?

Answer 17

• Pancreatic enzyme responsible for digesting protein
• Anti trypsin’s found in blood to neutralize its toxicity
• Can be effective test for pancreatitis in cats but short lived, not effective in dogs

Question 18

What is pancreatic lipase?

Answer 18

• Breakdown triglyceride in gut lumen
• Tests:
• immunoassays - expensive, has to be sent away for snap test, yes/no answer only
• certain biochemical assays - cheap, fast, in house, works in all species

Question 19

What are the signs of exocrine pancreatic insufficiency? how would you test for it?

Answer 19

• BAR, fails to put on weight, polyphagia, diarrhea and sometimes steatorrhea
• Acute onset, depression, emesis, shock, abdom pain
• Tests:
• Faecal analysis
• Serum TLI - specific to exocrine pancreas