Hepatobiliary Flashcards
Milk thistle MOA?
Silymarin is active extract
antioxidant, free radical scavenger, inhibits lipid peroxidation, retards hepatic collagen formation
What are branch chain AAs?
valine
leucine
isoleucine
SAMe MOA?
hepatoprotectice
antioxidant
antiinflammatory
precursor to glutathione
ALT half life in dogs vs cats?
dog: 17-60 h
cat: 3.5 h
Ursodeoxycholic acid MOA?
antiinflammatory immunomodulation antifibrotic promotes choleresis decreases toxic effects of bile acids
zinc MOA
- essential trace mineral
- enhances ureagenesis
- increased glutathione peroxidase activity
- antifibrotic
Histologic lesion most common for drug/toxin hepatopathy?
centrilobular necrosis
How is ammonia produced?
End product of AA, purine, and amine breakdown by bacteria, metabolism of glutamine by enterocytes, and breakdown of urea by bacterial ureases
Ammonia is rapidly converted to ____ in the liver.
urea or glutamine
What does alkalosis cause with HE?
Pushes NH4+ to NH3 which can diffuse into the CNS
T/F: dogs with chronic hepatitis or more likely to have fever and abdominal pain than dogs with active hepatitis
False- acute is painful with fever, chronic more likely to have ascites
T/F: hepatomegaly is more common in acute hepatitis
True
List some mechanisms (pathophys) of hepatocellular injury
tissue hypoxia, lipid peroxidation, intracellular cofactor depletion, intracellular toxin production, cholestatic injury, endotoxic insults, hepatocyte plasma membrane injury
Why are hepatocytes especially susceptible to anoxia?
liver receives a mixture of venous and arterial blood
what does hypoxic damage to the liver lead to?
plasma membrane and cytosolic organelle injury secondary to ATP depletion; free radicals may cause oxidative cellular injury
how does cholestasis injure the liver?
leads to retention of bile acids that directly damages cellular organelles
how do endotoxins damage the liver?
stimulation of inflammatory cells to produce inflammatory mediators (prostaglandins and leukotrienes) that perpetuate inflammation in the liver; TNFalpha plays an important role as well
how does TNFalpha perpetuate hepatitis?
stimulates hepatocyte apoptosis through the Fas-Fas ligand pathway
Name categories and specific diseases causing hepatitis and cholangiohepatitis in dogs and cats
Idiopathic=canine chronic hepatitis, feline cholangitis complex, nonspecific reactive hepatitis
Viral- adenovirus type I, acidophil cell hepatitis, herpesvirus (neonates), FIP
Bacterial- feline cholangitis complex, Lepto, Bartonellosis, Tyzzer’s dz, Salmonellosis, Listeriosis, Tularemia, Brucellosis, Helicobacter, Septicemia, Mycobacteria
Rickettsial- Ehrlichiosis, RMSF
Protozoal- toxo, neospora, leishmania, cytauxzoonosis, hepatozoonosis, coccidiosis
Parasitic- visceral larval migrans, dirofilariasis, liver fluke migration, schistomiasis, echinoccocus cysts
Fungal- Histo, blasto, coccidioides, aspergillosis, phycomycosis
Algal- protothecosis
Hepatotoxins- acetaminophen, aflatoxin, amiodarone, aspirin, azathioprine, azoles, carprofen, diazepam, halothane, methimazole, lomustine, phenobarb, tetracyclines, TMS, xylitol,, zonisamide
What are the two categories of feline cholangitis complex
neutrophilic vs lymphocytic cholangitis
T/F: neutrophilic cholangitis typically appears histologically as neutrophilic infiltration within the wall or lumen of the intrahepatic bile ducts
True
T/F: lymphocytic cholangitis typically appears histologically as neutrophilic infiltration within the wall or lumen of the intrahepatic bile ducts
False- lymphocytic typically is mixed inflammatory infiltrate (lymphocytes +/- plasma cells) within portal areas, associated with varying degrees of fibrosis and bile duct hyperplasia
What can be seen on histopath with chronic neutrophilic hepatitis that is different from acute neutrophilic hepatitis?
varying degrees of fibrosis and bile duct hyperplasia
What underlying conditions can be associated with neutrophilic cholangitis in cats?
IBD, pancreatitis