Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
Horm Metab Res. 2011 May;43(5):337-42. doi: 10.1055/s-0031-1271693. Epub 2011 Feb 17.
In nonhuman primates and rodents, melatonin acting directly on the adrenal gland, inhibits glucocorticoid response to ACTH. In these species, an intrinsic adrenal circadian clock is involved in ACTH-stimulated glucocorticoid production. We investigated whether these findings apply to the human adrenal gland by determining i) expression of clock genes in vivo and ii) direct effects of melatonin in ACTH-stimulated adrenal explants over a) expression of the clock genes PER1 (Period 1) mRNA and BMAL1 [Brain-Muscle (ARNT)-like] protein, ACTH-induced steroidogenic acute regulatory protein (StAR), and 3β-hydroxysteroid dehydrogenase (3β-HSD) and b) over cortisol and progesterone production. Adrenal tissue was obtained from 6 renal cancer patients undergoing unilateral nephrectomy-adrenalectomy. Expression of the clock genes PER1, PER2, CRY2 (Cryptochrome 2), CLOCK (Circadian Locomotor Output Cycles Kaput) and BMAL1, was investigated by RT-PCR in a normal adrenal and in an adenoma. In independent experiments, explants from 4 normal adrenals were preincubated in culture medium (6 h) followed by 12 h in: medium alone; ACTH (100 nM); ACTH plus melatonin (100 nM); and melatonin alone. The explants' content of PER1 mRNA (real-time PCR) and StAR, 3β-HSD, BMAL1 (immuno slot-blot), and their cortisol and progesterone production (RIA) were measured. The human adrenal gland expresses the clock genes PER1, PER2, CRY2, CLOCK, and BMAL1. ACTH increased PER1 mRNA, BMAL1, StAR, and 3β-HSD protein levels, and cortisol and progesterone production. Melatonin inhibited these ACTH effects. Our study demonstrates, for the first time, direct inhibitory effects of melatonin upon several ACTH responses in the human adrenal gland.
在非人类灵长类动物和啮齿动物中，褪黑素直接作用于肾上腺，抑制促肾上腺皮质激素（ACTH）对糖皮质激素的反应。在这些物种中，内在的肾上腺生物钟参与了 ACTH 刺激的糖皮质激素产生。我们通过确定 i）体内时钟基因的表达和 ii）褪黑素对 ACTH 刺激的肾上腺外植体的直接作用，来研究这些发现是否适用于人类肾上腺：a）时钟基因 PER1（Period 1）mRNA 和 BMAL1 [脑-肌肉（ARNT）样] 蛋白的表达，ACTH 诱导的类固醇急性调节蛋白（StAR）和 3β-羟甾脱氢酶（3β-HSD），以及 b）皮质醇和孕酮的产生。从 6 名因单侧肾切除术-肾上腺切除术而接受手术的肾癌患者中获得肾上腺组织。通过 RT-PCR 研究了正常肾上腺和腺瘤中时钟基因 PER1、PER2、CRY2（隐色素 2）、CLOCK（Circadian Locomotor Output Cycles Kaput）和 BMAL1 的表达。在独立的实验中，将来自 4 个正常肾上腺的外植体在培养基中预孵育 6 小时，然后在：培养基中单独孵育；ACTH（100 nM）；ACTH 加褪黑素（100 nM）；和褪黑素单独孵育。用实时 PCR 测量外植体 PER1 mRNA 的含量，用免疫印迹法测量 StAR、3β-HSD、BMAL1（免疫槽印迹）以及皮质醇和孕酮的产生（RIA）。人类肾上腺表达时钟基因 PER1、PER2、CRY2、CLOCK 和 BMAL1。ACTH 增加了 PER1 mRNA、BMAL1、StAR 和 3β-HSD 蛋白水平，以及皮质醇和孕酮的产生。褪黑素抑制了这些 ACTH 作用。我们的研究首次证明了褪黑素对人类肾上腺中几种 ACTH 反应的直接抑制作用。
