Muscle

Question 1

4 enzymes elevated in skeletal muscle injury

Answer 1

1. CK
2. AST
3. LDH
4. ALT

Question 2

CK isoenzymes aid in localization

Answer 2

• CK1
   - Brain/CSF (not in serum)
• CK2 
   - cardiac (human)
• CK3
   -  SKELETAL /cardiac muscle specific!!

Question 3

Why is total LDH excluded in muscle injury

Answer 3

• too non-specific (5 isoenzymes)
• imperceptible hemolysis –> ↑ LDH
  
  • *not helpful!!

Question 4

5 causes of skeletal muscle injury –> ↑ total CK

Answer 4

1. Myositis
2. Trauma
3. Strenuous exercise
4. Equine Rhabdomyolysis
5. Hypokalemia
6. 2° to arthritis

Question 5

Enzyme patterns in CK
• Hepatochellular injury
• mild to moderate muscle injury
• active, severe muscle damage & hepatocelllular injury

Answer 5

• VERY sensitive to muscle injury
  • IM injections
• poor “stick” –> muscle damage/hemolysis –> ↑
  • w/o obvious clinical signs –run it again!
  -SHORT 1/2 life = 4 hrs

Question 6

Enzyme patterns in AST
• Hepatochellular injury
• mild to moderate muscle injury
• active, severe muscle damage & hepatocelllular injury

Answer 6

• Hepatocyte & myocyte injury
• longer 1/2 life than CK
• Must have ALT or CK to determine liver vs muscle

Question 7

Enzyme patterns in ALT
• Hepatochellular injury
• mild to moderate muscle injury
• active, severe muscle damage & hepatocelllular injury

Answer 7

PRIMARILY LIVER!!!!

– severe muscle damage/congenital myopathy

Question 8

Neonatal value of CK

Answer 8

5X adult

• ~7 month = adult values

Question 9

Non-enzyme parameters for muscle damage

Answer 9

1. Myogloninuria
      • Severity
2. Potassium (  CK release
        --> myocyte necrosis 
        --> myoglobinuria

Question 10

Common causes of Severe hypokalemia

Answer 10

1. Feline CKD
   • K wasting PU
2. Diabetes mellitus
3. Post-partum dairy cow w/ ketosis

– 2&3 - Ketones –> ↓ K+ absorption from GI

Question 11

What is a negative effect of Ketones

Answer 11

↓ K absorption @ gut

Question 12

What are 3 tx for Post-partum dairy ketosis?

Answer 12

1. Glucose
2. Insulin
3. Mineralocorticoids

** directly ↓ K+ further –> total body depletion