Elias L L, Antunes-Rodrigues J, Elias P C, Moreira A C
Department of Medicine, Faculty of Medicine, Ribeirão Preto, Brazil.
J Clin Endocrinol Metab. 1997 Apr;82(4):1243-7. doi: 10.1210/jcem.82.4.3884.
The objective of the present study was to examine the effect of changes in plasma osmolality (pOsm) on the responses of the pituitary-adrenal axis to CRH and atrial natriuretic peptide (ANP) release in patients with central diabetes insipidus (DI). Eight normal subjects and six DI patients were subjected to human CRH (hCRH) (1 microgram/kg) stimulation alone or associated with isotonic volume loading (0.9% NaCl, 12 mL.kg.60 min) or an osmotic stimulus (5% NaCl, 0.06 mL.kg/min.120 min). The DI group showed significantly increased pOsm and undetectable or low plasma arginine vasopressin (AVP) during all tests. In the control group, pOsm and plasma AVP increased only during the osmotic stimulus. The DI group presented lower plasma ANP levels than controls during osmotic stimulus and isotonic volume loading. The lower ANP secretion in DI patients corroborates the importance of neurohypophyseal hormones in ANP regulation. Basal plasma ACTH and cortisol levels did not differ between controls and DI. The latter group presented a higher ACTH response than controls during stimulation with hCRH alone [area under the curve (AUC) 1138 +/- 99 vs. 709 +/- 62 pmol.L/min] and hCRH/5% NaCl (AUC 1602 +/- 209 vs. 1158 +/- 187 pmol.L.min). The DI cortisol AUC were higher than controls during stimulation with hCRH alone (65,471 +/- 6,070 vs. 48,062 +/- 3,476 nmol.L.min) and hCRH/5% NaCl (89,005 +/- 10,043 vs. 62,105 +/- 5,600 nmol.L.min). The highest ACTH and cortisol responses to hCRH in both groups were obtained with hCRH/5% NaCl. There was a significant correlation between mean pOsm and ACTH response to hCRH (r = 0.62). The increased responses to hCRH with increasing pOsm were present in control subjects and in patients with DI. However, at any given level of pOsm, there was no difference in ACTH response between controls and DI. These data indicate that the acute increases in pOsm augmented the ACTH and cortisol responses to hCRH that involve other factors besides magnocellular AVP.
本研究的目的是检测血浆渗透压（pOsm）变化对中枢性尿崩症（DI）患者垂体-肾上腺轴对促肾上腺皮质激素释放激素（CRH）和心房利钠肽（ANP）释放反应的影响。8名正常受试者和6名DI患者分别接受单独的人CRH（hCRH）（1微克/千克）刺激，或与等渗容量负荷（0.9%氯化钠，12毫升·千克·60分钟）或渗透刺激（5%氯化钠，0.06毫升·千克/分钟·120分钟）联合刺激。DI组在所有测试中pOsm显著升高，血浆精氨酸加压素（AVP）检测不到或水平较低。在对照组中，pOsm和血浆AVP仅在渗透刺激期间升高。在渗透刺激和等渗容量负荷期间，DI组的血浆ANP水平低于对照组。DI患者较低的ANP分泌证实了神经垂体激素在ANP调节中的重要性。对照组和DI组的基础血浆促肾上腺皮质激素（ACTH）和皮质醇水平无差异。在后一组中，单独用hCRH刺激时（曲线下面积[AUC]1138±99对709±62皮摩尔·升/分钟）以及用hCRH/5%氯化钠刺激时（AUC 1602±209对1158±187皮摩尔·升/分钟），ACTH反应高于对照组。单独用hCRH刺激时（65471±6070对48062±3476纳摩尔·升/分钟）以及用hCRH/5%氯化钠刺激时（89005±10043对62105±5600纳摩尔·升/分钟），DI组的皮质醇AUC高于对照组。两组对hCRH的最高ACTH和皮质醇反应是在hCRH/5%氯化钠刺激时获得的。平均pOsm与对hCRH的ACTH反应之间存在显著相关性（r = 0.62）。随着pOsm升高，对照组受试者和DI患者对hCRH的反应均增加。然而，在任何给定的pOsm水平，对照组和DI组之间的ACTH反应无差异。这些数据表明，pOsm的急性升高增强了对hCRH的ACTH和皮质醇反应，这涉及除大细胞AVP之外的其他因素。
