Bravo E L, Tarazi R C, Fouad F M, Textor S C, Gifford R W, Vidt D G
Hypertension. 1982 May-Jun;4(3 Pt 2):193-9.
Two sets of studies were performed in 13 patients with proved adrenal pheochromocytoma to test the hypothesis that the sympathetic nervous system (SNS) is active and might contribute to the hypertensive state. Similar studies were performed in 15 additional patients considered to have essential hypertension. In the first set, 13 patients with pheochromocytoma were subjected to head-up tilt to assess the activity of the SNS. This maneuver decreased diastolic blood pressure in only two; heart rate increased appropriately in all except one. Changes in plasma norepinephrine (NE) were variable and did not correlate with changes in blood pressure (BP) and heart rate (HR). In the second set, 10 patients with pheochromocytoma were given a single oral dose of clonidine (0.3 mg) to evaluate what role, if any, the SNS might contribute to the hypertensive state. Fifteen patients with essential hypertension were studied similarly for comparison. Clonidine produced significant decreases in BP and HR but left plasma renin activity unchanged in both groups. In essential hypertension, the cardiovascular responses were accompanied by significant reductions in plasma NE. By contrast, plasma NE was unchanged in patients with pheochromocytoma, despite similar reductions in BP and HR. These results suggest that the sympathetic reflexes are intact in pheochromocytoma, and that much of the hypertension associated with these tumors may be related to increased sympathetic activity.
对13例已证实患有肾上腺嗜铬细胞瘤的患者进行了两组研究，以验证交感神经系统（SNS）活跃且可能导致高血压状态这一假说。对另外15例被认为患有原发性高血压的患者进行了类似研究。在第一组研究中，对13例嗜铬细胞瘤患者进行头高位倾斜试验以评估SNS的活性。该操作仅使2例患者的舒张压降低；除1例患者外，所有患者的心率均适当增加。血浆去甲肾上腺素（NE）的变化各不相同，且与血压（BP）和心率（HR）的变化无关。在第二组研究中，给10例嗜铬细胞瘤患者口服单次剂量的可乐定（0.3 mg），以评估SNS在高血压状态中可能起到的作用（若有）。对15例原发性高血压患者进行了类似研究以作比较。可乐定使两组患者的BP和HR均显著降低，但血浆肾素活性未发生变化。在原发性高血压患者中，心血管反应伴随着血浆NE的显著降低。相比之下，嗜铬细胞瘤患者的血浆NE未发生变化，尽管其BP和HR也有类似程度的降低。这些结果表明，嗜铬细胞瘤患者的交感反射是完整的，且与这些肿瘤相关的大部分高血压可能与交感活性增加有关。
