43. Clinical biochemistry of the hypothalamus, hypophysis
- Dynamic function test
- Administer insulin -> measure cortisol, GH
- Administer GnRH -> measure FSH, LH
- Administer TRH -> measure TSH
- GH excess
- Administer oral glucose -> GH still high (usually decreases)
- GH deficiency
- Low levels of IGF-1
- Administer GHRH -> GH still low (usually increases)
- Hyperprolactinaemia
- Serum prolactin
- Administer dopamine agonist -> prolactin still high (usually decreases)
- Diabetes insipidus
- Water deprivation -> urine osmolality unchanged (usually increases)
- Administer desmopressin -> urine osmolality increases (normalizes)