Research Article

Growth hormone releasing factor: comparison of two analogues and demonstration of hypothalamic defect in growth hormone release after radiotherapy.

Br Med J (Clin Res Ed) 1984; 288 doi: https://doi.org/10.1136/bmj.288.6433.1785 (Published 16 June 1984) Cite this as: Br Med J (Clin Res Ed) 1984;288:1785
  1. A Grossman,
  2. N Lytras,
  3. M O Savage,
  4. J A Wass,
  5. D H Coy,
  6. L H Rees,
  7. A E Jones,
  8. G M Besser

    Abstract

    Human pancreatic growth hormone releasing factor (hpGHRF(1-40] stimulates the release of growth hormone in normal subjects and some patients with growth hormone deficiency. A study comparing the shorter chain amidated analogue hpGHRF(1-29) with an equivalent dose of hpGHRF(1-40) in seven normal subjects showed no significant difference in growth hormone response between the two preparations. Six patients with prolactinomas were also tested; these patients had received megavoltage radiotherapy previously but had developed growth hormone deficiency as shown by insulin induced hypoglycaemia. In all six patients 200 micrograms hpGHRF(1-40) or hpGHRF(1-29)NH2 produced an increase in the serum growth hormone concentration. These data suggest that hpGHRF(1-29)NH2 may be useful for testing the readily releasable pool of growth hormone in the pituitary and that cases of hypothalamo-pituitary irradiation resulting in growth hormone deficiency may be due to failure of synthesis or delivery of endogenous GHRF from the hypothalamus to pituitary cells.