[Diagnostic use of the GRF test in the study of GH secretion]

A good response after an intravenous bolus of GRF-1-29 NH2 in patients with hypopituitary dwarfism localities the site of the GH-deficiency in the hypothalamus (GRF deficiency). These patients could be treated with GH and GRF. Never the less some patients with hypothalamic responses after TRH don't respond after GRF. Probably these non responders need GRF in pulsatile or prolonged administration and T4 substitution before and during the test if TSH is also deficient. At least some cases without GRF response can be accepted as pure pituitary only GH would be effective.