Hepatic

Question 1

Types of HE

Answer 1

-A: acute liver failure
-B: portosystemic bypass, no intrinsic liver disease
-C: cirrhosis, portal hypertension, acquired portosystemic collateral blood vessels

Question 2

How is ammonia produced?

Answer 2

In GI tract, urease producing bacteria produce ammonia by breaking down nitrogenous products (urea).

Question 3

Ammonia detoxification pathways

Answer 3

1) ammonia converted to urea by peripheral hepatocytes -> urea can be excreted by the kidneys
2) ammonia is synthesized into glutamine by perivenous hepatocytes

In liver failure, the ability of the liver to metabolize ammonia to either urea or glutamine is reduced -> hyperammonia

Question 4

Ammonia in cerebrum

Answer 4

-Cerebrum has glutamine synthetase activity (in astrocytes)
-Ammonia passes freely across BBB
-Astrocytes form glutamine, release it back into systemic circulation
-Too much can cause atrocyte swelling

Question 5

Most common cause of HE in dogs

Answer 5

Congenital and acquired portosystemic shunts

Question 6

Most common clinical signs of HE in dogs

Answer 6

Altered mentation, head pressing, ataxia, seizures, vomiting, lethargy, ptyalism, apparent blindness, shaking

Question 7

Most common signs of HE in cats

Answer 7

ptyalism, anorexia, weakness, vomiting, lethargy

Question 8

What amino acid are cats with hepatic lipidosis deficient in?

Answer 8

Arginine