Casanueva F F, Burguera B, Tome M A, Lima L, Tresguerres J A, Devesa J, Dieguez C
Department of Medicine, Faculty of Medicine, Compostela University, Santiago de Compostela, Spain.
Neuroendocrinology. 1988 Jan;47(1):46-9. doi: 10.1159/000124889.
In humans, corticoids suppress growth hormone (GH) secretion elicited by a variety of stimuli, while in vitro they potentiate GH release. To further study this problem, the effect of two doses of dexamethasone on GH secretion elicited by GH-releasing hormone (GHRH) in 6 normal volunteers was studied. Each subject underwent three tests, on 3 separate days with GHRH 1-29 (1 microgram/kg i.v. at 12.00 h). On the control day, only GHRH was given, on the second day dexamethasone 4 mg i.v. was administered at 09.00 h (3 h before GHRH) and on the third day dexamethasone 8 mg p.o. was given 12 h before GHRH (at 00.00 h). The GHRH-induced GH peak was 9.9 +/- 2.0 ng/ml, while 4 mg dexamethasone significantly (p less than 0.05) potentiated GH secretion elicited by GHRH (29.2 +/- 5.7 ng/ml). When dexamethasone 8 mg was given 12 h before, GHRH-induced GH secretion was completely blocked (3.0 +/- 1.1 ng/ml) (p less than 0.05). These results indicate that corticoids have two different actions: an acute potentiating activity on GHRH, and a delayed blocking action on GHRH-induced GH secretion.
在人类中，皮质激素会抑制多种刺激引发的生长激素（GH）分泌，而在体外它们却能增强GH释放。为了进一步研究这个问题，我们研究了两种剂量的地塞米松对6名正常志愿者中由生长激素释放激素（GHRH）引发的GH分泌的影响。每位受试者在3个不同的日子里接受了三项测试，均静脉注射1 - 29的GHRH（12.00时，1微克/千克）。在对照日，仅给予GHRH；在第二天，于09.00时（在GHRH前3小时）静脉注射4毫克地塞米松；在第三天，于00.00时（在GHRH前12小时）口服8毫克地塞米松。GHRH诱导的GH峰值为9.9±2.0纳克/毫升，而4毫克地塞米松显著（p＜0.05）增强了GHRH引发的GH分泌（29.2±5.7纳克/毫升）。当在12小时前给予8毫克地塞米松时，GHRH诱导的GH分泌被完全阻断（3.0±1.1纳克/毫升）（p＜0.05）。这些结果表明，皮质激素有两种不同的作用：对GHRH的急性增强活性，以及对GHRH诱导的GH分泌的延迟阻断作用。
