Giustina A, Bossoni S, Bussi A R, Pozzi A, Wehrenberg W B
Cattedra di Clinica Medica, University of Brescia.
Endocr Res. 1993 Mar;19(1):47-56. doi: 10.1080/07435809309035407.
Attenuated plasma GH secretion during sleep and blunted GH responses to provocative stimuli have been observed in patients with Cushing's disease. Synthetic porcine galanin elicits GH secretion when given alone, and enhances the GH response to GHRH in normal human subjects. The aim of our study was to investigate the effects of galanin on the GH response to GHRH in patients with Cushing's disease. We studied 5 female subjects with untreated active Cushing's disease caused by micro-pituitary adenomas (age 43 +/- 6.7 years; BMI 30 +/- 0.7 kg/m2). Four normal adult females, matched for age and body weight with the patients with Cushing's disease, were studied as controls. Subjects underwent in random order: (1) infusion of synthetic porcine galanin IV, 500 micrograms in 100 mL; (2) infusion of saline, IV, 100 mL. A bolus of human GHRH(1-29)NH2 (Geref, Serono, Italy), 100 micrograms in 1 mL saline, was injected IV at 0 minutes. Patients with Cushing's disease showed blunted GH peaks after GHRH (1.2 +/- 0.4 micrograms/L) during saline infusion, as compared to normal controls (24.6 +/- 4.6 micrograms/L; p < 0.05). During galanin infusion a significantly enhanced GH response to GHRH, as compared with saline infusion, was observed in control subjects (GH peak: 51.4 +/- 9.8 micrograms/L; p < 0.05), but not in patients with Cushing's disease (GH peak: 2.3 +/- 0.6 micrograms/L). GH levels were significantly lower both after saline and after galanin in patients with Cushing's disease as compared to normal controls. Our data demonstrate that galanin is not able to enhance the GH response to GHRH in patients with Cushing's disease. That galanin cannot reverse this effect suggests that the mechanism of action of galanin is not via a decrease in somatostatin release by the hypothalamus.
在库欣病患者中，已观察到睡眠期间血浆生长激素（GH）分泌减弱以及GH对刺激物的反应迟钝。单独给予合成猪甘丙肽可引发GH分泌，并增强正常人类受试者对生长激素释放激素（GHRH）的GH反应。我们研究的目的是调查甘丙肽对库欣病患者GH对GHRH反应的影响。我们研究了5名由微垂体腺瘤引起的未经治疗的活动性库欣病女性受试者（年龄43±6.7岁；体重指数30±0.7kg/m²）。选取4名年龄和体重与库欣病患者相匹配的正常成年女性作为对照。受试者按随机顺序接受：（1）静脉输注合成猪甘丙肽，100mL中含500微克；（2）静脉输注生理盐水，100mL。在0分钟时静脉注射1mL生理盐水中含100微克的人GHRH(1 - 29)NH₂（Geref，赛诺菲，意大利）。与正常对照组（24.6±4.6微克/L；p<0.05）相比，库欣病患者在输注生理盐水期间给予GHRH后GH峰值降低（1.2±0.4微克/L）。在输注甘丙肽期间，与输注生理盐水相比，在对照受试者中观察到对GHRH的GH反应显著增强（GH峰值：51.4±9.8微克/L；p<0.05），但在库欣病患者中未观察到（GH峰值：2.3±0.6微克/L）。与正常对照组相比，库欣病患者在输注生理盐水和输注甘丙肽后GH水平均显著降低。我们的数据表明，甘丙肽不能增强库欣病患者对GHRH的GH反应。甘丙肽不能逆转这种效应表明甘丙肽的作用机制不是通过减少下丘脑生长抑素的释放。
