Volta C, Bernasconi S, Iughetti L, Ghizzoni L, Rossi M, Costa M, Cozzini A
Department of Pediatrics, University of Parma, Italy.
Eur J Endocrinol. 1995 Jun;132(6):716-21. doi: 10.1530/eje.0.1320716.
To clarify the possible neuroendocrine mechanisms underlying the impairment in growth hormone (GH) secretion present in obesity, the GH response to GH-releasing hormone (GHRH, N = 6), insulin hypoglycemia (N = 6), clonidine (N = 7) and arginine (N = 8) after GHRH pretreatment (1 microgram/kg iv 2 h before the tests) was evaluated in 27 obese peripubertal children and in a group of normal-weight short-normal children (N = 26). Growth hormone-releasing hormone pretreatment and all further stimuli elicited a statistically significant GH response in both obese and short-normal children; in the latter group arginine did not induce a significant GH response. No differences were found among the GH responses after the second stimuli in obese children, while in short-normal children the arginine peak and area values were lower than after GHRH and clonidine. Comparison between the two groups showed similar baseline but higher stimulated GH levels in normal-weight children after all tests except arginine, after which no difference was present. In conclusion, the neuroregulation of GH release seems to be similar qualitatively in normal-weight and obese youngsters; the different behavior observed after arginine, which is supposed to act through somatostatin inhibition, might be due to a chronic increase in somatostatinergic tone responsible for the lower stimulated GH levels in obesity.
为阐明肥胖症患者生长激素（GH）分泌受损可能的神经内分泌机制，我们对27名青春期前肥胖儿童和一组体重正常但身材矮小的儿童（N = 26）进行了研究，评估在生长激素释放激素（GHRH，N = 6）、胰岛素低血糖（N = 6）、可乐定（N = 7）和精氨酸（N = 8）刺激下，GHRH预处理（测试前2小时静脉注射1微克/千克）后的GH反应。生长激素释放激素预处理及所有后续刺激在肥胖儿童和身材矮小但正常的儿童中均引发了具有统计学意义的GH反应；在后者中，精氨酸未诱导出显著的GH反应。肥胖儿童第二次刺激后的GH反应之间未发现差异，而在身材矮小但正常的儿童中，精氨酸峰值和面积值低于GHRH和可乐定刺激后的值。两组比较显示，除精氨酸刺激后无差异外，所有测试后体重正常儿童的基线相似，但刺激后的GH水平更高。总之，正常体重和肥胖青少年中GH释放的神经调节在性质上似乎相似；精氨酸被认为通过抑制生长抑素起作用，观察到的不同表现可能是由于生长抑素能张力的慢性增加导致肥胖症患者刺激后的GH水平较低。
