Lecture 16: Liver and Skeletal Muscle Flashcards
(130 cards)
1
Q
Are enzymes when healthy at a low or high constant level
A
low
2
Q
enzyme activity can be increased due to ___ or __
A
leakage or induction
3
Q
leakage enzymes are present in __and/or __
A
cytosol and/or organelles
4
Q
leakage enzyme are present at __levels in the cell
A
high
5
Q
Usually Leakage enzymes __rapidly post injury
A
increase
6
Q
T or f: cell has to die for leakage enzymes to be released
A
false
7
Q
inducible enzymes are attached to __
A
cell membranes
8
Q
what does the liver produce
A
- Cholesterol
- Glucose
- Plasma proteins (albumin, acute phase proteins, coag factors)
9
Q
t or f: liver produces immunoglobulins
A
false
10
Q
what are some functions of liver
A
- Production of cholesterol, glucose, plasma proteins
- Storage of iron and copper
- Detoxification- excretion of wastes, converts ammonia to urea
- Bile production and excretion
- Bile acid metabolism
- Bilirubin metabolism
11
Q
T or f: magnitude of serum enzyme activity correlates with reversibility of injury or hepatic function
A
false
12
Q
what occurs in hepatocellular injury or necrosis
A
leakage of cytosolic enzymes into ECF—> increased enzyme activity in blood
13
Q
magnitude of hepatocellular leakage or necrosis depends on what
A
- Number of hepatocytes affected
- Severity of injury
- Serum half-life of enzymes
14
Q
what are our leakage/necrosis enzymes
A
- ALT
- AST
- SDH
- LDH
- GLDH
15
Q
what enzyme is best indicator of liver damage in dogs and cats
A
ALT
16
Q
t or f: ALT liver specific
A
true
17
Q
what is the main exception of increase ALT that is not from liver damage
A
severe muscle injury
18
Q
what are some causes of increase ALT activity
A
- Hypoxia or ischemic necrosis
- Metabolic
- Neoplasia
- Nutritional
- Inflammatory
- Toxic
- Inherited
- Trauma
19
Q
what are some things that can cause hypoxia or ischemic necrosis leading to increase ALT
A
anemia, decreased BF, hepatic congestion
20
Q
what are some metabolic disorders that increase ALT
A
hepatic lipidosis, diabetes mellitus, hyperthyroidism
21
Q
what are some nutritional causes of increase ALT
A
copper toxicity, hemochromatosis
22
Q
what are some inherited diseases that can cause increase ALT
A
copper storage disease, lysosomal storage disease
23
Q
What magnitude of increase in ALT occurs with acute injury
A
extreme injury ALT >1000
24
Q
t or f: AST is liver specific
A
false
25
when would you see increases in AST
1. Liver injury
2. Muscle injury
3. Hemolysis
26
what muscle enzyme is used to detect hepatocellular injury in ruminants and horses
AST
27
If AST is high in dogs and cats assess in combination with __ to determine if due to hepatocellular damage
ALT
28
if AST is high in ruminants and horses assess with __ to determine if due to hepatocellular damage
SDH
29
if AST is high with __indicates muscle injury
CK
30
t or f: SDH is a liver specific enzyme
true
31
what species is SDH useful in to assess hepatic injury
horses and ruminants
32
t or f: LDH is liver specific
false
33
what can cause an increase in LDH
1. Hepatocellular injury
2. Muscle damage
3. Hemolysis
34
t or f: GLDH is liver specific
true
35
define cholestasis
interruption or obstruction of bile flow
36
define intrahepatic cholestasis
within The bile canaliculi or ductless of the liver
37
38
define extra hepatic cholestasis
within the gallbladder or common bile duct
39
What membrane bound hepatic enzymes that can be induced by cholestasis and increase
1. GGT
2. ALP
40
in addition to GGT and ALP ___ may increase due to retention or reflex of bile from cholestasis
bilirubin/bile acids
41
what Are the 3 isoenzymes of ALP
1. Liver ALP (L-ALP)
2. Corticosteroid ALP (C-ALP)
3. Bone ALP (B-ALP)
42
what can cause increase in total serum ALP
1. Cholestasis (degenerative, metabolic, neoplastic, inflammatory, etc)
2. Induction by drugs or hormones
3. Hyperthyroidism
4. Cushings
5. Increased osteoblastic activity (young animals)
6, pancreatitis
7. Neoplasia
8. DM
9. Colic
43
what drugs or hormones can increase ALP
1. Phenobarbital
2. Corticosteroids
3. Thyroxine
44
what ALP isoenzyme is sensitive measure of cholestasis in dogs
liver ALP (L-ALP)
45
what liver enzyme is more useful for cholestasis identification in large animals
GGT
46
in cats ALP often increases with __
hepatic lipidosis
47
the half life of L-ALP in cats is __therefore anytime you see an increase in ALP in cats its significant
6-8hrs
48
what species is Corticosteroid ALP only useful in
dogs
49
50
Increases in C-ALP is often see with increase __ because it can also be induced by steroids
L-ALP
51
what breed may have high ALP due to C-ALP due to possible adrenal dysfunction
Scottish terriers
52
what are some causes of increase B-ALP
1. Young, growing animals
2. Lytic/proliferative bone lesions (fractures, neoplasms, hyperparathyroidism)
3. Benign familial hyper phosphate is
53
what breed has benign familial hyperphosphatemia and therefore increase B-ALP
siberan huskies
54
Increase serum GGT is due to induction in __ or __
Hepatocytes or biliary epithelium
55
GGT is more sensitive for cholestasis in what species compared to ALP
cats, horses and ruminants
56
High levels of GGT found in __ of dogs, sheep and cattle, resulting in marked GGT in neonates
colostrum
57
what liver enzyme can be useful indicator of passive transfer
GGT
58
__< 1 month old can have GGT up to 3x adult levels
foals
59
t or f: high GGT in foals is form colostrum
false
60
what are the components of bile
water, cholesterol, bile acids, bilirubin, inorganic acids
61
what are the 3 main functions of bile
1. Excretory
2. Facilitates digestion (lipids and fat-soluble vitamins)
3. Buffers of acidic pH of ingesta
62
unconjugated bilirubin is waste product of __
heme breakdown
63
What is process of unconjugated bilirubin becoming conjugated
1. Bound to albumin in blood
2. Taken up by liver
3. Conjugated in liver
64
what happens to conjugated bilirubin
1. Conjugation occurs in liver
2. Excreted into bile canaliculi
3. Enters intestines
4. Makes way into blood, urine and/or feces
65
66
clinical icterus occurs when tbili >__
1.5mg/dL
67
what are the 3 general causes of increase tbili
1. Pre-hepatic
2. Hepatic
3. Post-hepatic
68
pre-hepatic hyperbilirubinemia is an increased production of __bilirubin
unconjugated/indirect
69
what are some causes of pre-hepatic hyperbilirubinemia
associated with increase RBC breakdown
1. IMHA and other hemolytic anemias
2. Transfusion reactions
3. Hemoparasites
70
what are some causes of hepatic hyperbilirubinemia
1. Decreased hepatic uptake of unconjugated bilirubin by hepatocytes
2. Decreased conjugated of bilirubin
3. Sepsis associated cholestasis/functional cholestasis
71
Is unconjugated or conjugated bilirubin increased with hepatic hyperbilirubinemia
either or both
72
What is general cause of post-hepatic hyperbilirubinemia
obstructive cholestasis (physical obstruction)
73
Is conjugated or unconjugated bilirubin increased with post-hepatic hyperbilirubinemia
conjugated
74
wha are some causes of post-hepatic hyperbilirubinemia
1. Inflammation or neoplasia in or near biliary system
2. Cholestasis/cholangitis
3. Pancreatitis
4. Hepatic lipidosis
75
What other blood work signs would be indicative of pre-hepatic hyperbilirubinemia
Spherocytes, Heinz bodies, positive Coombs tests
Evidence of hemolytic anemia
76
if patient has increase ALP, GGT and hyperbilirubinemia what does that suggest
cholestasis disease, post-hepatic hyperbilirubinemia
77
Is Pre-hepatic, hepatic, or post-hepatic uncommon to see with bilirubinuria
pre-hepatic because only conjugated bilirubin enters urine
78
> or=__% of functional hepatocytes must be lost before serum biochemical abnormalities are detected
70%
79
what are some mechanisms of decreased functional hepatic mass
1. Hepatocellular injury or necrosis
2. Hepatic fibrosis
3. Hepatic atrophy
80
what are the 2 tests to evaluate hepatic function
1. Hepatic pseudo function tests
2. Hepatic function tests
81
what does hepatic pseudo function test evaluate
Livers synthetic ability- can it produce things
82
what does hepatic function test evaluate
Livers ability to clear substances from teh blood
83
what are you evaluating in hepatic pseudo function tests
1. Albumin
2. BUN
3. Glucose
4. Cholesterol
84
will often see decrease in albumin, BUN, glucose and cholesterol with __ or __
PSS or end stage liver failure
85
what is main site for synthesis of coagulation factors
liver
86
if you have decreased functional hepatic mass what would you expect to happen to coagulation factors and PT, PTT
decrease coagulation factors, prolonged PT and PTT
87
t or f: patients with liver disease blood excessively
false
88
what is being measured with hepatic function tests
1. Bilirubin
2. Bile acids
3. Ammonia
89
bile acids are synthesized in the liver from __
cholesterole
90
how do you measure bile acids
Take pre- and post-prandial samples (2hrs after high fat meal)
91
after feeding during bile acids test most bile acids should be reabsorbed from circulation within __hrs
2hrs
92
>__ (dogs) and __(cats) bile acids is considered abnormal in post-prandial sample
>25-30, >25
93
in __species you do not do pre and post-prandial sample for bile acids because they lack gallbladder
horses
94
what are some causes of increase bile acids
1. PSS
2. Cholestasis
3. Inappropriate gallbladder contraction
4. Hepatic insufficiency/failure
95
what are some causes of decreased bile acids
small intestine disease (ideal malabsorption)
96
most ammonia is converted to __in liver and __enters systemic circulation
urea, urea
97
what are some causes of hyperammonemia
1. Hepatic insufficiency/ failure
2. PSS
3. Ruminants fed excessive urea or non-protein nitrogen
4. Intestinal disorders in horses
98
how Must you sample ammonia because very volatile
Plasma must be separated from cells within 30 minutes of collection and refrigerated within 1 hr of collection
99
liver receives O2 rich rich blood from __ and nutrient rich blood from __
hepatic artery, portal vein
100
Are congenital or acquired PSS more common
congenital
101
___PSS more common in small breed dogs whereas __ common in large breed dogs
extrahepatic, intrahepatic
102
do cats get intra or extrahepatic PSS
extrahepatic
103
acquired PSS is secondary to severe __
cirrhosis
104
are patients with acquired or congenital PSS very jaundiced
acquired
105
what are some common lab findings with PSS
decreased pseudo function test
1. Hypoalbunemia
2. Decreased BUN
3. Hypoglycemia
4. Hypocholesterolemia
106
in addition to lab findings associated with decreased pseudo function tests what other lab finding is seen in patients with congenital PSS
increased bile acids- usually post prandial BA
107
in addition to decreased pseudo function tests in PSS what other sign is seen in acquired PSS
both pre and post-BA are increased and patients often icteric
108
in both acquired and congenital PSS does ammonia increase or decrease
increase
109
what type of anemia is seen with PSS
microcytosis +/- mild non-regenerative anemia
110
what is USG with PSS
hyposthenuria or isosthenuria
111
t or f: ALT and ALP often normal with PSS
true
112
what type of crystal is seen with PSS
ammonium biurate
113
what are some causes of acute hepatitis
1. Infectious
2. Drugs
3. Chemicals
114
what are some lab findings consistent with acute hepatitis
1. Mild to marked increase in ALT, AST, and SDH
2. Mild to moderate increase in ALP and GGT
3. Increase tbili
115
What are some lab findings consistent with chronic hepatitis
1. Variable increase in leakage enzymes
2. Increased inducible enzymes
3. May be icteric
4. Decreased pseudo function tests
5. Increase BA and ammonia
6. Normalization or decreased liver enzyme activity
116
what are some causes of steroid hepatopathy
1. Cushings
2. Glucocorticoids administration
117
what are some lab findings consistent with steroid hepatopathy
1. Increase ALP (increase C-ALP)
2. Increase GGT
3. Bilirubin WRI
118
what are some lab findings consistent with hepatic lipidosis
1. Marked increase ALP
2. Hyperbilirubinemia
3. Increase BA
119
increases in __, __, and __ with __ is suggestive of hepatic lipidosis in cats
ALP, AST, ALT, with hyperbilirubinemia
120
cats with other cholestasis liver diseases besides hepatic lipidosis usually see greater increase in __compared to __
GGT, ALP
121
what enzymes are indicator of muscle injury
1. CK
2. AST
3. LDH
122
what is most specific enzyme for muscle injury
CK
123
what are some causes of increase CK
1. Trauma- IM injections, colic, extreme exercise
2. Inflammation: myositis
3. Degenerative: HYPP, muscular dystrophy, lysosomal storage disease
4. Metabolic: equine rhabdomyolysis, malignant hyperthermia
5. Ischemic myopathies
6. Anorexia in cats
7. Difficult venipuncture
124
assess __ and __ together to differentiate liver vs. muscle damage
CK and AST
125
if both AST and CK are increased then increase AST is due to __
muscle injury
126
if AST, CK and ALT is increased then likely __ and __
muscle and liver injury
127
if only CK is increased then __
early muscle injury
128
if only AST is increased then __ vs__
previous muscle injury vs hepatocelllular injury
129
t or f: myoglobin is sensitive and specific for muscle damage
true
130
what are some urinalysis findings that support myoglobin
discolored urine (red/brown) and heme reaction of urine dipstick
