GROWTH-HORMONE RELEASE BY THE NOVEL GH RELEASING PEPTIDE HEXARELIN INPATIENTS WITH HOMOZYGOUS BETA-THALASSEMIA

Patients with beta-thalassemia often present with abnormalities in gro wth and other endocrine functions. Growth hormone (GH) secretion is co ntrolled via somatostatin and growth hormone releasing hormone (GHRH). Recently, Hexarelin, a new potent GH secretagogue (His-D-2-Methyl-Trp -Ala-Trp-D-Phe-Lys-NH2), was synthesized. Our study was designed to as sess and compare its efficacy as a GH secretagogue to GHRH 1-29 in bet a-thalassemia. Eighteen patients, regularly transfused and chelated, w ere studied; 11 were short statured. None had diabetes mellitus, hypot hyroidism, hypoparathyroidism or major organ failure. We measured GH a t 0, 30, 60, 90, 120 min after GHRH 1-29 or Hexarelin administration. Hexarelin p.o. or i.v. evoked a brisk rise of serum GH which was signi ficantly higher (p < 0.01) than that induced by GHRH 1-29 i.v. In conc lusion, Hexarelin has greater GH releasing capacity than GHRH 1-29 at 1 mu g/kg i.v. and can thus be viewed as a potential therapeutic agent in GH deficient states.