Powerpoint 7

Question 1

What is the dominant second messenger system of:

1. ACTH?
2. GH?
3. PRL?
4. LH?
5. FHS?
6. TSH?

Answer 1

1. cAMP
2. STAT
3. STAT
4. cAMP
5. cAMP
6. cAMP

Question 2

What are the two forms of GH?

Answer 2

Major 22 kDa, Minor 20 kDa – may be subtle differences in the levels of bioactivity and glycosylation

Question 3

What is human GH used to treat? How many cadavers are req’d?

Answer 3

pituitary dwarfism - 6000 cadavers

Question 4

What is Jacob Kreutzfeld disease?

Answer 4

problems with prion contamination

Question 5

What are the two direct actions of GH?

Answer 5

1. Mobilization of energy (anti-insulin like effects)

2. Promotion of cell differentiation

Question 6

What is one indirect action of GH?

Answer 6

Promotion of growth and endocrine effects – Induction of IGF-I that promotes cell division and has insulin-like effects

Question 7

What are direct effects of GH?

Answer 7

1. Reduced glucose transport and metabolism - reduction in insulin receptors (ex. liver)
2. Increase AA transport - into muscle, liver, adipose cells
3. increase protein synthesis - increases in both transcription and translation (ex. in liver leading to mitosis)
4. Increased IGF production - from the liver and other cells (pituitary and fibroblasts where it acts locally)
5. Increased fibroblast differentiation (chondrocyte, osteoblast & adiposity formation)

Question 8

What is an indirect effect of GH?

Answer 8

Promotion of growth endocrine effects - Via IGFs: bone, soft tissue, gonads and viscera; clonal expansion of chondrocytes

Question 9

IGF-I & IGF-II: GH dependent or GH independent?

Answer 9

1. GH dependent

2. GH independent

Question 10

What is IGF-I produced by? What is it released into and how does it act?

Answer 10

Liver - released into the blood stream and acts in an endocrine fashion