Growth

Question 1

What are the provocative agents used for GH testing and how do they work?

Answer 1

Remember ABCDEG:

Inhibits somatostatin to increase GHRH:
- Arginine
- B-blockers like propanolol

Stimulates release of GHRH directly:
- Clonidine (a2 adrenergic agonist)
- Dopamine agonists (Levodopa)
- Exercise

Glucagon causes hyperglycemia followed by hypoglycemia, which triggers counterregulatory release of GH.