Plasma growth hormone (gh) response to gh-releasing factor in normal children with short stature and patients with pituitary dwarfism

Abstract

Synthetic human pancreatic GRF (hpGRF-44)was administered as an iv bolus to 28 normal children with short stature and 27 patients with GH deficiency. After a dose of 1 or 2± hpGRF-44/kg BW, mean plasma GH levels peaked at 15 and 30 min, respectively, with corresponding values of 30.1 α 4.7 and 33.2 α 3.7 (αSE) ng/ml in normal but short children. The overall plasma GH response was greater than that of other GH stimulation tests such as insulin-induced hypoglycemia, glucagon-propranolol or L-dopa administration. Plasma LH, FSH, TSH, PRL, and cortisol levels were not altered by hpGRF- 44 injection. Sixteen of 27 patients with GH deficiency did not respond to a 2±/kg BW hpGFR-44. However, plasma GH increases to greater than 5 µg/ml occurred in the remaining 11 patients. Their GH levels reached peaks between 15 and 90 min, with values ranging between 5.8 and 17.8 ng/ml. Two of these responding patients were infused iv with hpGRF-44 at 2.5±g/min for 90 min after receiving an iv bolus injection of 2±/kg BW. Their plasma GH levels increased and remained near peak values throughout the infusion period. However, no increase in plasma GH levels occurred after a second bolus injection of hpGRF-44 given at the end of the infusion. These results suggest that hpGRF-44 is useful for the diagnosis of GH deficiency in individuals with short stature and thatsome patients with GH deficiency, diagnosed on the basis of established tests, have GH responses to hpGRF-44. © 1984 by The Endocrine Society.