Diabetes Mellitus

Question 1

Actions of insulin on glucose, protein and lipid in the body?

Answer 1

Decrease hepatic glucose output and increase muscle glucose uptake
Decrease proteolysis
Decrease lipless and ketogenesis

Question 2

What is GLUT-4, where is it expressed and how does it affect glucose uptake?

Answer 2

Glucose Transporter 4
Expressed in muscle and adipose tissues where it lies in vesicles until recruited by insulin
Results in 7x increase in glucose uptake into the cell

Question 3

What percentage of energy expenditure is protein metabolism responsible for and what contrasting effects do insulin and cortisol have on it?

Answer 3

20% of energy expenditure
Insulin inhibits proteolysis (to prevent gluconeogenesis)
Cortisol stimulates proteolysis to increase blood glucose

Question 4

What are the different fuel stores and which releases the most energy per gram?

Answer 4

Carbohydrates
Protein
Fat - highest energy released per gram

Question 5

What are the lengths of time the fuel stores hold energy for?

Answer 5

Carbs - 16 hours (short term)
Protein - 15 days (longer term)
Fat - 30-40 days (longest term source)

Question 6

Effect of insulin on fat metabolism (triglycerides specifically) in adipose tissue and in circulation? (they’re different)

Answer 6

In circulation - stimulates breakdown of triglycerides into glycerol and non-esterified fatty acids for uptake into adipose tissue
In adipose tissue - stimulates formation of triglycerides from non-esterified fatty acids and glycerol-3-P
Decreases gluconeogenesis and ketogenesis