Summary OBJECTIVE Hexarelin is a recently synthesized small growth hormone releasing peptide (GHRP) (His-D-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2). It Is actlve by intra-venous, oral and intranasal administration In animals and man. The aim of this study was to find out whether longterm administration of this peptlde would promote growth In short chlldren. DESIGN AND PATIENTS intranasal hexareiin was administered in a dose of 60 pglkg thrice dally to 8 prepubertal short children aged 4-11-6 years for perlods of up to months. RESULTS Hexarelln treatment stimulated Insulin-like growth factor-i (IGF-I) secretion ralsing the level from 10.4 ± 3.9 (SD) to 141 f 46 nmoill (P < 0.004). The rise IGF-l led to a significant Increase In the mean (±SD) linear growth velocity from 53 ± 08 to 8 3 ± 1.7 cm/year (P < 0.0001). There was also a slgniflcant decrease skinfold thickness despite Increase in body weight and an Increase in head circumference. Additional flndlngs were a rlse in serum phosphate from 1–5 ± 01 to 1–8 ± 01 mmoi/l (P < 0004) and of aikallne phosphatase from 219 ± 74 to 261 ± 75 U/l (P < 005). CONCLUSIONS The long-term GHIIGF-I stimulating, anabolic and growth promoting effects achieved by intranasai administration of this hexapeptide, seemingly without undeslrable slde-effects, suggests clinical potential for this new class of drugs.
