Plasma GH response to the sequential 3 day administrations of GHRH followed by arginine infusion in patients with idiopathic GH deficiency and normal short children.

HANEW, K., UTSUMI, A., SUGAWARA A., SHIMIZU, Y., TAZAWA, S. and ABE, K. Plasma GH Response to the Sequential 3 Day Administrations of GHRH Followed by Arginine Infusion in Patients with Idiopathic GH Deficiency and Normal Short Children. Tohoku J. Exp. Med., 1993, 169 (2), 91-101 - To study the site of lesions in idiopathic growth hormone (GH) deficiency (IGHD), growth hormone releasing hormone (GHRH) was administered sequentially for 3 days to 19 patients with IGHD, 3 patients with GH deficiency (GHD) secondary to hypothalamic tumors, and 7 normal short children (NSC). GHRH (100μg) was injected as a bolus on days 1 and 3, and was infused over 60min on day 2. Of 19 patients with IGHD, 6 showed an improved GH response (group A), 5 a decreased response (group B) and the remaining 8 an unchanged response (group C) to sequential administration of GHRH. The response was unchanged in patients with secondary GHD or NSC. There was no significant correlation between the patterns of GH response and the findings on pituitary MR images or the delivery state at birth in IGHD patients. Ten patients with IGHD (4 of group A; 3 each of groups B & C) and 2 NSC showed much greater GH responses to arginine (0.5g/kg i.v. for 30min) injected with preceding GHRH than to arginine injected without preceding GHRH. These results indicate that hypothalamic lesions were primarily responsible for GH deficiency in about 60% of the patients with IGHD (groups A and B), and group C might have more severe hypothalamo-pituitary damages than the other groups. Hypothalamic somatostatin neurons seems to be functioning to a degree even in severe IGHD patients. -idiopathic GH deficiency; normal short children; GH; GHRH; arginine