Enzymes

Question 1

(ALT)

1. interpretation?
2. SA vs LA?
3. mild to mod increase ween with what endocrinopathies?

Answer 1

1. liver damage

(musc dmg if very severe)

2. liver specific in SA, not used in LA
3. DM, hyperthryoid (cats), cushings (dogs), +/- hypothyroidism (dogs)

Question 2

(AST)

1. interpretation?

Answer 2

1. hepatocyte or muscle damage (skeletal)

(severe hemolysis rare)

Question 3

(SDH)

1. interpretation?

Answer 3

1. liver dmg in LA

(more specific but less sens than ALT in LA)

Question 4

(CK)

1. interpretation?

Answer 4

1. muscle damage

(VERY sens, mild ^ nonspecific and assoc w/ iatrogenic in LA)

Question 5

(ALP)

1. origin?
2. mech?
3. General Interpretation?

Answer 5

1. hepatocytes, biliary epi, bone
2. ^prod
3. post-hepatic cholestasis (esp w/ ^GGT, bilirubin) +/- cholesterol w/ time/severity

induction by drugs/hormones (corticosteroids, anticonvulsants, metabolic - hyperthyroid, cushings, DM)

^osteoblastic activity (mild): young animals, bone dz

Question 6

(GGT)

1. origin?
2. mech?
3. interpretation?

Answer 6

1. biliary epi, hepatocytes, renal tubular cells, colostrum
2. ^prod
3. post hepatic cholestasis or biliary hyperplasia

induction by drugs/hormones (like ALP)

general liver dz marker in LA

colostrum ingestion

Question 7

(Amylase)

1. origin?
2. mech?
3. not used in what species?
4. general interpretation?

Answer 7

1. pancreas, intestine, liver
2. dmg, dec clearance
3. LA, cats
4. pancreatic acinar dmg (esp if very high)

GI dz

decreased GFR (2-3x increase)

Question 8

(Lipase)

1. origin?
2. mech?
3. not used in what spec?
4. interp?

Answer 8

1. pancreatic acinar cells
2. dmg, dec clearance, maybe ^prod in some cases
3. LA
4. pancretic acinar dmg (esp if marked)

dec GFR

neoplasia, corticosteroid tx?

Question 9

(Trypsin-like immunoreactivity)

1. what kind of assay?
2. decreased = ?
3. increased = ?

Answer 9

1. immunologic..
2. exocrine pancreatic insufficiency
3. dec renal clearance, pancreatic path, intestinal dz

Question 10

1-3. What are the three mechanisms for increased serum activity?

Answer 10

1. release from damaged cells
2. increased production
3. reduced clearance

Question 11

1. how specific/sens are enzyme elevations?

Answer 11

1. they lack both sens and spef

Question 12

(ALP)

(species diff)

1. dog?
2. cat?
3. horse?

Answer 12

1. corticosteroids, phenobarb, colostrum (<10 days), bone (young large, OSA, repair)
2. hyperthyroidism (< 4x url), late term preg (placental ALP)
3. colic, bone growth in foals, not affected by colostrum

Question 13

(GGT spec diff)

1. dog?
2. cat?
3. horse?
4. cow?

Answer 13

1. like ALP but no bone
2. lipidosis may have high ALP, normal GGT
3. high in neonatal, used as generic screening test for liver dz
4. colostrum, generic screening test for liver dz