Chiodera P, Coiro V
Cattedra di Endocrinologia, Università di Parma, Italy.
Brain Res. 1987 Sep 8;420(1):178-81. doi: 10.1016/0006-8993(87)90257-5.
The inhibitory action of oxytocin (OT) on adrenocorticotropin (ACTH) secretion has been disputed. Thus we evaluated the effect of exogenous OT on the elevated blood ACTH levels in normal human subjects. Metyrapone, a blocker of cortisol secretion, was given to enhance ACTH release. This experimental model was chosen because metyrapone-induced ACTH activation depends on diminution of the negative feed-back of cortisol, which is an important physiological mechanism in the control of ACTH secretion. A striking decline in plasma cortisol levels and a 10-fold rise in the mean plasma ACTH concentration was observed within 20 h after the beginning of metyrapone treatment (750 mg orally every 4 h). The administration of OT (2 IU as a i.v. bolus plus 4 IU infused in 2 h) significantly reduced the metyrapone-induced plasma ACTH rise. Since the effect of OT was evident when ACTH secretion was enhanced by a reduced cortisol-dependent negative feed-back, confirmation of the inhibitory action of OT on the ACTH secretory system in man is provided.
催产素（OT）对促肾上腺皮质激素（ACTH）分泌的抑制作用一直存在争议。因此，我们评估了外源性OT对正常人类受试者升高的血液ACTH水平的影响。给予美替拉酮，一种皮质醇分泌阻滞剂，以增强ACTH释放。选择这个实验模型是因为美替拉酮诱导的ACTH激活依赖于皮质醇负反馈的减弱，这是控制ACTH分泌的一个重要生理机制。在美替拉酮治疗开始后20小时内（每4小时口服750毫克），观察到血浆皮质醇水平显著下降，平均血浆ACTH浓度升高了10倍。静脉推注OT（2国际单位加在2小时内输注4国际单位）显著降低了美替拉酮诱导的血浆ACTH升高。由于当通过减少皮质醇依赖性负反馈增强ACTH分泌时OT的作用明显，因此证实了OT对人类ACTH分泌系统的抑制作用。
