The response of normal subjects and patients with idiopathic growth hormone deficiency to continuous infusion of human pancreatic growth hormone releasing factor 1-44.

The GH response to a prolonged continuous infusion of human pancreatic growth hormone releasing factor (hpGRF 1-44), 0.3 microgram/kg/h was evaluated in seven patients with severe idiopathic GH deficiency, one patient with partial deficiency and in seven normal controls. Normal controls had a multiphasic response with a first peak between 15 and 90 min of 13.6 to 88.5, mean 45.6 mU/l and a second peak between 105 and 195 min of 8.8 to 73.1, mean 33.8 mU/l. However, the magnitude and pattern of response were highly variable. Six of the seven patients with severe GH deficiency had a response with a maximum level between 30 and 90 min of 3.3 to 7.5, mean 4.8 mU/l. Mean levels remained greater than 2.0 mU/l throughout the infusion but further peaks were absent or minimal. The patient with partial GH deficiency responded in a normal manner. hpGRF 1-44 by continuous infusion thus induced GH release in seven of eight patients with idiopathic GH deficiency though the response was impaired and the pattern of secretion abnormal in severely deficient patients.