Small Ani. Med 2- Hepatic Introduction 2

wilsbach's version from 2016-02-28 14:59

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Question Answer
what are bile acids/how are they formed? how do bile acids become bile? exs of bile acids?There are Primary bile acids (made in the liver) and secondary/tertiary bile acids (made by bacterial transformation). In the liver, bile acids are made by the liver taking cholesterol, doing CYP450 to it to make bile acids (Ex's: Cholic, chenodeoxycholic, Deoxycholic, lithocholic). When taurine or glycine is added, it becomes bile which is secreted into the intestine. Bile is highly "recycled" meaning there is 98% recirculation after uptake in ileum (enterohepatic circulation)
what is Cholecystokinin and how does it relate to bile acids?It is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. It comes from intestinal cells and is released in reaction to food. The CCK directly stimulates the gall bladder to contract, increasing the bile acids
explain the Serum Bile Acids Test...what can it tell us? what DOESNT it tell us?BACKGROUND: Ok. So. Liver takes cholesterol. Makes bile acids. turns them into bile. put them in gall bladder. Gall bladder deposits them in poop. Because of entero-hepatic circulation (high recycling) the bile is re-absorbed from intestines as bile acids and is in the blood as such. In a healthy liver, the portal blood goes to the liver and the liver sucks up the bile acids again. If the liver ISNT healthy, it doesnt suck them up, so there are higher levels of bile acids in the blood than normal .......TEST: take a 12hr fasted serum sample, test for level of bile acids. Then Feed a small amount of dog food, and take a 2 hour postprandial serum sample. LABS say a preprandial sample should be less than 5-10mmol and postprandial sample should be <15-25. Elevation of the post-prandial sample means the liver isn't sucking them up right. Just tells you there is dec fxn of liver. but it cant tell you WHY there is dec fxn, and the amount of elevation doesnt tell you if it's reversible or not
when is doing a serum bile acids test pointless?if they are icteric-- obv they will be high, bc if the liver is jacked enough to the point where you are yellow, obv it isnt absorbing bile acids
what if your preprandial sample is higher than your postprandial sample?Spontaneous gallbladder contraction pre test (maybe smelled food)
what will serum bile acids test results be like if there is ileal dz?post-prandial BAs will be LOW bc ileum is site of reuptake
what does a Resting Ammonia Concentration test tell you (what dzs?) cautons with this test?can test for Hepatic encephalopathy, Indicates reduced hepatic mass or shunting in dogs. Additionally, can do post prandial measurement. can also do a Challenge test. *caution: blood ammonia very labile, only have 10min when it is on ice. For the challenge/tolerance test, Ammoniumchloride 2ml/kg rectal, blood at: t0 - t20 - t40 min (see if liver can elim it, and at what rate)
which breed normally has unusual ammonia levels (slightly higher)irish wolfhound
what will normal dog ammonia test response be like? PSS dog?
what is an awesome tx for chronic liver dzs, and when is the times you can use this tx? when is it CI?you can tx chronic with glucocorticoids because Anti-inflammatory and anti-fibrotic via Ito...however that means you can only use this as tx EARLY in the chronic dz, which means you must have had to dx via bx. Contraindicated in acute hepatitis!!!!
list of txs for liver dzUrsodiol, SAM-e, Vit E, Zinc, Lactulose, silymarin, Anti-fibrotics (corticos—earlier if Biopsy, Colchicine – end stage) Antibiotics (Lepto, Necrotizing hepatitis)
*****Ursodiol--- aka and aka? what does it do/how does it work? (4 things it does) aka Ursodeoxycholic acid/UDCA. It is a Synthetic primary bile acid!!! It Influences balance of natural bile acids!! This is important bc BAs=more lipophilic=more toxic. lithocholic(type of BA)= most toxic=> apoptosis (cell death) & oxidative damage. SO, UDCA does: (1) Displacement of toxic bile acids (flush effect) (2) Increased bile flow (active secretion from hepatocytes) (3) “immunemodulation” to prevent autoimmune reactions (4) Increased production of glutathione + metallothionein (conjugative enzymes which detox stuff)
**when is ursodiol CI?Contraindicated in biliary duct obstruction!!! (it has a flushing effect/inc bile flow, so if there is a blockage, you are making it worse)
**what 2 dzs is ursodiol particularly useful for?Especially usefull in destructive cholangiolitis, Best choice for chronic hepatitis of unknown ethiology
how should you dose ursodiol?(she said dont need to know dosages but she loves this thing so maybe just recognize the numbers: 7.5 mg/kg/day q 12 h) Start slow and watch for abdominal cramping, diarrhea
SAM-e and Vit E....what are these? why are we using them to treat liver dz? how do they work?They are antioxidants! donor of methyl, sulfhydryl, and aminopropyl groups--> oxidative stress defense + GSH production (glutathione ie conjugating enzyme ie detoxer)
why does zinc help with liver dz?zinc causes Metallothionein induction so if there is toxic levels of copper for instance, instead of the copper just diffusing from intestine to through cells to blood, the zinc is given and it activates metallothianines which bind up metals-- so then the excessive, toxic copper doesnt build up in the blood and screw up the liver
why give lactulose in HE?It causes soft stool (dec transit time in intestines-- less ammonia absorbed) and changes pH in the intestinal tract- if it makes the colon more acidic, it "traps" ammonia by ionizing it as NH4+ so it wont be absorbed by intestine (because there is enough of that already causing problems)
what is silymarin, why do we use it to tx liver dz?strong antioxidant, what it does is inc SOD (enzyme which breaks down Reactive oxygen species)-- is Effective against mushroom toxin phalloidine and acetaminophen (extracted from milk thistle)
what should diet of HE dog be made like?Moderate protein restriction: Dog: 2g / kg / day 15 -20% of dry matter..... Cat: 3–4g / kg / day 30-35% of dry matter (cats as obligate carnivores need more protein obv)