Ghigo E, Miola C, Aimaretti G, Valente F, Procopio M, Arvat E, Yin-Zhang W, Camanni F
Department of Clinical Pathophysiology, University of Turin, Italy.
Metabolism. 1992 Sep;41(9):1000-3. doi: 10.1016/0026-0495(92)90127-V.
Acute hyperglycemia inhibits the growth hormone (GH) response to several stimuli including growth hormone-releasing hormone (GHRH), likely acting by stimulation of endogenous somatostatin release. The aim of our study was to verify whether arginine ([Arg] 30 g intravenously [IV] in 30 minutes), a well-known GH secretagogue likely acting via inhibition of hypothalamic somatostatin release, counteracts the inhibitory effect of oral glucose (OG) administration (100 mg orally) on the GH response to GHRH (1 micrograms/kg IV bolus) in seven normal subjects (aged 20 to 30 years). The GH response to GHRH (peak, 11.6 +/- 1.8 micrograms/L) was inhibited by previous OG load (peak, 7.4 +/- 0.8 micrograms/L; P less than .02 v GHRH alone) and potentiated by Arg coadministration (peak, 36.2 +/- 8.8 micrograms/L; P less than .03 v GHRH alone). The potentiating effect of Arg on the GHRH-induced GH increase was unaffected by previous OG load (peak, 30.4 +/- 6.9 micrograms/L). In conclusion, our results show that Arg abolishes the inhibitory effect of OG administration on the GHRH-induced GH response in man. These data, although indirect, suggest that both acute hyperglycemia and Arg act at the hypothalamic level, stimulating and inhibiting, respectively, the release of somatostatin.
急性高血糖会抑制生长激素（GH）对多种刺激的反应，包括生长激素释放激素（GHRH），其作用可能是通过刺激内源性生长抑素的释放来实现的。我们研究的目的是验证精氨酸（30分钟内静脉注射[IV]30克），一种可能通过抑制下丘脑生长抑素释放而起作用的著名生长激素促分泌素，是否能抵消口服葡萄糖（OG，口服100毫克）对7名正常受试者（年龄20至30岁）生长激素对生长激素释放激素（GHRH，静脉推注1微克/千克）反应的抑制作用。生长激素对生长激素释放激素的反应（峰值，11.6±1.8微克/升）被先前的口服葡萄糖负荷所抑制（峰值，7.4±0.8微克/升；与单独使用生长激素释放激素相比，P<0.02），而精氨酸联合给药可增强该反应（峰值，36.2±8.8微克/升；与单独使用生长激素释放激素相比，P<0.03）。精氨酸对生长激素释放激素诱导的生长激素增加的增强作用不受先前口服葡萄糖负荷的影响（峰值，30.4±6.9微克/升）。总之，我们的结果表明，精氨酸消除了口服葡萄糖给药对人体生长激素释放激素诱导的生长激素反应的抑制作用。这些数据虽然是间接的，但表明急性高血糖和精氨酸都作用于下丘脑水平，分别刺激和抑制生长抑素的释放。
