Newell-Price J, Perry L, Medbak S, Monson J, Savage M, Besser M, Grossman A
Department of Endocrinology, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom.
J Clin Endocrinol Metab. 1997 Jan;82(1):176-81. doi: 10.1210/jcem.82.1.3674.
To assess the ability of desmopressin to differentiate between pituitary and ectopic ACTH-dependent Cushing's syndrome and to determine whether diagnostic accuracy could be improved by administering it together with human sequence CRH, we examined its effects on cortisol and ACTH secretion when given alone or in combination with CRH in patients with Cushing's syndrome of varied etiology and compared these data to the results of a standard CRH test in the same individuals. Each patient was studied on three occasions, in random order, separated by at least 48 h. At 0900 h, via an indwelling forearm cannula, 10 micrograms desmopressin, 100 micrograms CRH, or a combination of the two were given as an iv bolus; thereafter, blood was drawn every 15 min for 2 h. The responses to the individual agents were determined according to the timing and calculation criteria suggested by Nieman et al. (1993). A total of 25 patients with Cushing's syndrome were studied: 17 patients with pituitary-dependent Cushing's syndrome, Cushing's disease (CD); 5 patients with occult ectopic ACTH secretion (EC); and 3 patients with primary adrenal (ACTH-independent) Cushing's syndrome. In this series, the best discrimination among ACTH-dependent patient groups was achieved using the combined test. Using the responses of plasma cortisol, all 17 patients with CD showed a rise greater than any of the 5 patients with EC, whereas 1 patient with CD showed a plasma ACTH response within the range seen in the patients with EC. Plasma cortisol responses to desmopressin alone were seen in 14 of 17 patients with CD and 1 of 5 patients with EC and, after CRH alone, in 15 of 17 patients with CD but in no patient with EC. In contrast, plasma ACTH responses after CRH alone were seen in 14 of 17 patients with CD and 2 of 5 patients with EC and, after desmopressin alone, in 12 of 17 with CD and 3 of 5 with EC, thus indicating overlapping responses between the groups and poorer discrimination. No responses were seen in the ACTH-independent group. These data indicate that desmopressin causes the secretion of ACTH and cortisol in patients with ACTH-dependent Cushing's syndrome, and that in combination with CRH, it may provide an improvement over the standard CRH test in the differential diagnosis of ACTH-dependent Cushing's syndrome. Furthermore, these data suggest that there may be abnormalities in vasopressin receptor function or number in ACTH-secreting tumors.
为评估去氨加压素区分垂体性和异位促肾上腺皮质激素（ACTH）依赖性库欣综合征的能力，并确定联合使用人序列促肾上腺皮质激素释放激素（CRH）是否可提高诊断准确性，我们研究了去氨加压素单独使用或与CRH联合使用时，对不同病因库欣综合征患者皮质醇和ACTH分泌的影响，并将这些数据与同一患者标准CRH试验的结果进行比较。每位患者分三次接受研究，随机排序，每次间隔至少48小时。上午9点，通过留置的前臂静脉套管，静脉推注10微克去氨加压素、100微克CRH或两者的组合；此后，每15分钟采血一次，共采集2小时。根据Nieman等人（1993年）建议的时间和计算标准确定对各药物的反应。共研究了25例库欣综合征患者：17例垂体依赖性库欣综合征患者，即库欣病（CD）；5例隐匿性异位ACTH分泌（EC）患者；3例原发性肾上腺（ACTH非依赖性）库欣综合征患者。在该系列研究中，联合试验在ACTH依赖性患者组间的鉴别效果最佳。根据血浆皮质醇反应，所有17例CD患者的皮质醇升高幅度均大于5例EC患者中的任何一例，而1例CD患者的血浆ACTH反应在EC患者所见范围内。17例CD患者中有14例、5例EC患者中有1例出现了单独使用去氨加压素后的血浆皮质醇反应，单独使用CRH后，17例CD患者中有15例出现反应，但EC患者均无反应。相反，单独使用CRH后，17例CD患者中有14例、5例EC患者中有2例出现血浆ACTH反应，单独使用去氨加压素后，17例CD患者中有12例、5例EC患者中有3例出现反应，这表明两组反应存在重叠，鉴别效果较差。ACTH非依赖性组无反应。这些数据表明，去氨加压素可导致ACTH依赖性库欣综合征患者分泌ACTH和皮质醇，并且与CRH联合使用时，在ACTH依赖性库欣综合征的鉴别诊断中可能比标准CRH试验有所改进。此外，这些数据表明，ACTH分泌肿瘤中血管加压素受体功能或数量可能存在异常。
