title: Growth hormone releasing factor: comparison of two analogues and demonstration of hypothalamic defect in growth hormone release after radiotherapy.
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.
mesh_terms: D000328:Adult; D005260:Female; D013006:Growth Hormone / Q000097:blood* / Q000172:deficiency; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D007003:Hypoglycemia / Q000097:blood; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000532:radiotherapy*; D011388:Prolactin / Q000378:metabolism*; D017337:Sermorelin
chemical_list: D010446:Peptide Fragments; C036893:somatotropin releasing factor 40; D017337:Sermorelin; D011388:Prolactin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone