Bellone J, Aimaretti G, Bartolotta E, Benso L, Imbimbo B P, Lenhaerts V, Deghenghi R, Camanni F, Ghigo E
Department of Clinical Pathophysiology, University of Turin, Italy.
J Clin Endocrinol Metab. 1995 Apr;80(4):1090-4. doi: 10.1210/jcem.80.4.7714074.
The objective of this study was to verify the GH-releasing activity of a synthetic hexapeptide, hexarelin (HEX), before and during puberty. Ninety-six children (54 boys and 42 girls, aged 4.1-17.4 yr) were studied. Fifty-two of the children were prepubertal, and the other 44 were in pubertal stage II-IV. The GH response to 2 micrograms/kg HEX, iv (n = 56), was higher (P < 0.001) than that induced by 1 microgram/kg GHRH, iv (n = 33). The iv dose of 2.0 micrograms/kg HEX induced a greater GH increase (P < 0.02) than the 1.0 microgram/kg dose. The GH-releasing effect of 10 mg HEX, orally, was greater (P < 0.03) than that of 1.0 microgram/kg GHRH, iv (n = 7). The iv dose of 2 micrograms/kg HEX elicited an increase in GH levels that was higher in pubertal children than in prepubertal children (77.5 +/- 8.5 vs. 39.4 +/- 4.4 micrograms/L; P < 0.001). Before puberty, there was no sex-dependent difference in the GH response to HEX. It increased during puberty (P < 0.05 and P < 0.002 for boys and girls, respectively), when it was higher (P < 0.05) in girls than in boys. In contrast, GH responses to GHRH were not related to sex differences and/or puberty. In conclusion, HEX is a potent and reproducible stimulus of GH secretion in children. The effect of HEX increases in puberty, with girls showing a more marked GH response.
本研究的目的是验证一种合成六肽——六元瑞林（HEX）在青春期前及青春期期间的生长激素释放活性。对96名儿童（54名男孩和42名女孩，年龄4.1 - 17.4岁）进行了研究。其中52名儿童处于青春期前，另外44名处于青春期II - IV期。静脉注射2微克/千克HEX（n = 56）后生长激素（GH）反应高于静脉注射1微克/千克生长激素释放激素（GHRH）（n = 33）（P < 0.001）。2.0微克/千克的静脉注射剂量HEX比1.0微克/千克剂量诱导的GH升高更显著（P < 0.02）。口服10毫克HEX的GH释放作用大于静脉注射1.0微克/千克GHRH（n = 7）（P < 0.03）。静脉注射2微克/千克HEX引起的GH水平升高在青春期儿童中高于青春期前儿童（77.5±8.5对39.4±4.4微克/升；P < 0.001）。青春期前，对HEX的GH反应不存在性别差异。在青春期期间其升高（男孩和女孩分别为P < 0.05和P < 0.002），此时女孩的反应高于男孩（P < 0.05）。相比之下，对GHRH的GH反应与性别差异和/或青春期无关。总之，HEX是儿童生长激素分泌的一种强效且可重复的刺激物。HEX的作用在青春期增强，女孩表现出更明显的GH反应。
