Muscles

Question 1

What are some examples of muscle enzymes?

Answer 1

• Creatine kinase
• AST/ aspartate aminotransferase
• ALT/ alanine aminotransferase
• Lactate dehydrogenase

Question 2

What is exertional rhabdomyolysis?

Answer 2

muscle breakdown due to increased strenous exercise

Question 3

Why is the release of enzymes from muscle fibres slower than the release of enzymes from other sites in the body?

Answer 3

Because the enzymes released from muscle fibres enter plasma via the lymph

Question 4

What is the first muscle enzyme to peak after injury?

Answer 4

CK
it goes up first and then decreases fast (peaks around 6-12 hours after injury)
Then returns to the baseline within 48-72 hours after cessation of the injury

Question 5

How long can it take AST to reach a peak value?

Answer 5

24 hours or longer

Question 6

What are troponins indicative of?

Answer 6

muscle injury
they are released into circulation when the muscle fibres are damaged

Question 7

What is the troponin most commonly measured in veterinary medicine?

Answer 7

Cardiac Troponin I

Question 8

What may an increase in cardiac Troponin I reflect?

Answer 8

• Acute myocardial injury
• Cardiac trauma
• Cardiac disease
  (usually seen with cardiac damage)

Question 9

When are BNP and ANP released?

Answer 9

they increase with cardiac disease and there is increased release in response to ventricular and atrial overload

Question 10

What assay is used to measure BNP

Answer 10

a NT-ProBNP (highly sensitive)

Question 11

When is myoglobin released?

Answer 11

It is released following muscle cell damage

Question 12

What colour is myoglobin when excreted in the urine?

Answer 12

can result in a dark red/ reddish brown colour