VET 259 - Hepatobiliary assay exam

What is cholangiohepatitis?

inflammation of the liver and the biliary system

What does the root cholangio mean?

bile ducts

The liver is the _______ internal organ

largest

All functions of the liver are run by what?

enzymatic reactions

Metabolic functions of the liver?

metabolism of amino acids, carbohydrates, and lipids

What does the liver synthesize?

albumin, cholesterol, plasma proteins, and clotting factors

Liver secretes what?

bilirubin or bile

Liver eliminates what?

toxins

What is the primary function of the gallbladder?

store bile

Bile aids in what?

digestion

Triaditis is the inflammation of the _______, ________ and ________.

liver, pancreas and intestines

Gallbladder has relations with what other organ?

pancreas

Liver cells are ________ so damage in one zone will not affect all liver functions

compartmentalized

What are the 2 common analytes used to test hepatobiliary system function?

bilirubin and bile acid

What is bilirubin?

waste product that is an insoluble molecule

Bilirubin is byproduct of what?

RBC death

Bilirubin binds to ____ for transport to the liver

albumin

Bilirubin is metabolized and conjugated by what?

hepatic cells

Hepatic cells conjugate bilirubin to what molecule?

bilirubin glucuronide

Unconjugated bilirubin is found where?

Pre-hepatic

Increases in unconjugated bilirubin indicate what?

problem with uptake and a liver issue (liver not doing its job)

Conjugated bilirubin is found where?

Post-hepatic

Increased levels of conjugated bilirubin indicates what?

bile duct obstruction (liver did its job)

What are the bilirubin assays that are commonly performed?

total bilirubin, conjugated and unconjugated bilirubin

What species is biliverdin found in?

Avian species

Bile acids functions?

aid in fat absorption, modulate cholesterol levels

What are bile acids?

steroid acid synthesized in the hepatic cells

Where are bile acids stored?

gallbladder until contraction associated with feeding

What happens when bile reaches the ileum?

transported back to the portal circulation and back into the liver

What % of bile acids is actively resorbed in ileum? Where does the rest go?

90% to 95%. Remainder excreted in feces

Anything that interferes with circulation of bile acids causes what?

elevated numbers

Bile acids assay require a _____hr food fast

12 hours

Postprandial serum bile acid concentration are ______ than fasting concentration

higher

Explain bile acid assay

12hr fast → get sample → feed asap → 2hrs later get another sample

What can cause false results when testing bile acids?

inadequate fasting, food aromas, prolonged fasting or d+

Elevated bile acids indicate what?

some kind of liver disease

What is cholesterol?

plasma lipoprotein produced primarily in liver

Cholestasis causes increased levels of what?

cholesterol

cholesterol assays are used to screen for what? (3)

hypothyroidism, addison’s and cushing’s disease

As liver cells are damaged what happens to the enzymes?

enzymes leak into the blood

which enzyme levels rise the fastest after liver damage?

ALT (alanine transaminase)

how long will it take for ALT levels to return to normal?

2-3 weeks

which enzyme is bound to mitochondrial membrane?

AST (aspartate transaminase)

Since AST is bound to mitochondrial membrane what is required for it to be released?

More severe liver damage

What are common causes of AST elevation?

liver disease, muscle inflammation or necrosis, hemolysis

What can affect AST values?

hemolysis

what levels will rise in young animals during bone growth?

ALKP, ALP or AP - same thing

Alkaline phosphatase will be elevated with what?

cholestatis

ALKP will also be elevated as a response to ______?

corticosteroids (prednisone) also cushing’s disease

elevated levels of GGT are seen when?

liver disease → especially obstructive liver disease

what are the 2 major plasma proteins?

albumins and globulins

globulins are responsible for what production?

antibody

albumins are responsible for what?

osmolarity

what do liver function assays measure?

substances produced by the liver

what 2 assays aid in evaluating liver function?

bilirubin and bile acid

why can unconjugated bilirubin not be excreted?

because it is insoluble

T/F. If a patient is icteric the problem is definitely in the liver

false it can be after the liver → obstruction (stones…)

What is ALKP?

protein isoenzyme → help breakdown proteins

what is the function of GGT?

transfer amino acids across cell membranes