Leal-Cerro A, Pereira J L, Garcia-Luna P P, Astorga R, Cordido F, Casanueva F F, Dieguez C
Department of Endocrinology, Hospital Virgen del Rocio, Sevilla, Spain.
Clin Endocrinol (Oxf). 1990 Aug;33(2):291-5. doi: 10.1111/j.1365-2265.1990.tb00493.x.
Growth hormone (GH) secretion in patients with Cushing's syndrome is diminished to all the stimuli tested so far but the precise mechanisms through which this occurs are unknown. In order to investigate whether increased somatostatinergic tone might be responsible for this alteration, we studied the effect of pyridostigmine (120 mg p.o. at -60 min), which activates cholinergic synapses and thus suppresses hypothalamic somatostatin release on GH responses to GHRH (100 micrograms, i.v. at 0 min), in six patients with Cushing's syndrome. We found that while pyridostigmine markedly potentiated GH responses to GHRH, in all the normal subjects tested (n = 12), neither GHRH alone nor GHRH plus pyridostigmine elicited any increase in GH secretion in any of the patients with Cushing's syndrome. This suggests that chronic glucocorticoid excess induces marked alterations in the hypothalamic control of GH secretion.
库欣综合征患者对目前所测试的所有刺激的生长激素（GH）分泌均减少，但这种情况发生的确切机制尚不清楚。为了研究生长抑素能张力增加是否可能是这种改变的原因，我们在6例库欣综合征患者中研究了吡啶斯的明（在-60分钟口服120毫克）的作用，它激活胆碱能突触，从而抑制下丘脑生长抑素释放对GH对生长激素释放激素（GHRH，在0分钟静脉注射100微克）反应的影响。我们发现，虽然吡啶斯的明显著增强了GH对GHRH的反应，但在所有测试的正常受试者（n = 12）中，单独使用GHRH或GHRH加吡啶斯的明均未引起任何库欣综合征患者的GH分泌增加。这表明长期糖皮质激素过量会导致下丘脑对GH分泌的控制发生明显改变。
