Bauman W A, Spungen A M, Zhong Y G, Tsitouras P D
Spinal Cord Damage Research Center, Mt. Sinai Medical Center, New York, New York 10029.
J Clin Endocrinol Metab. 1994 May;78(5):1135-8. doi: 10.1210/jcem.78.5.8175969.
Human GH (hGH) secretion is stimulated by vigorous physical activity, whereas immobilization reduces its release. In paralyzed subjects with spinal cord injury (SCI), it has recently been shown that the release of hGH to provocative stimulation and plasma insulin-like growth factor-I (IGF-I) levels are reduced. The acute administration of baclofen, a gamma-aminobutyric acid derivative, has been shown to stimulate hGH release. The present study investigated the effect of chronic administration of baclofen on the provocative testing of hGH secretion and plasma IGF-I levels. Sixteen subjects with SCI were studied; eight subjects were treated (40-80 mg/day; > 6 months) with baclofen (Bac+), and eight were not (Bac-). Additionally, 8 non-SCI subjects were studied as controls. The groups were matched for gender and age. The subjects were not receiving any medications known to influence hGH secretion. After an overnight fast, arginine hydrochloride (30 g/subject) was infused iv over 30 min, with blood drawn for hormone determinations at baseline and 30, 60, 90, and 120 min. In the Bac- group compared with the Bac+ group, the arginine-stimulated mean plasma hGH levels at 30 and 60 min (P < 0.05) and peak and sum plasma hGH levels (P < 0.01) were reduced. There were no significant differences in the plasma hGH response between the Bac+ group and the control group. Plasma IGF-I levels may reflect the integrated tissue response to hGH. A significant inverse relationship was present between age and plasma IGF-I levels for the control and Bac+ groups, but not for the Bac- group. The mean plasma IGF-I level was significantly reduced in the Bac- compared with the Bac+ group. No significant differences in mean plasma IGF-I levels were noted between the Bac+ and control groups. SCI is associated with body composition changes and metabolic alterations that may be exacerbated by reduced activity of the hGH-IGF-I axis. Oral chronic baclofen therapy appears to reverse the deleterious effects of paralysis and immobilization on hGH physiology.
剧烈的体育活动可刺激人体生长激素（hGH）的分泌，而制动则会减少其释放。最近研究表明，在患有脊髓损伤（SCI）的瘫痪患者中，hGH对刺激性刺激的释放以及血浆胰岛素样生长因子-I（IGF-I）水平均降低。γ-氨基丁酸衍生物巴氯芬的急性给药已被证明可刺激hGH释放。本研究调查了长期服用巴氯芬对hGH分泌激发试验和血浆IGF-I水平的影响。研究了16名SCI患者；8名患者接受巴氯芬治疗（40 - 80毫克/天；> 6个月）（Bac+组），8名未接受治疗（Bac-组）。此外，研究了8名非SCI患者作为对照。各小组在性别和年龄上相匹配。受试者未服用任何已知会影响hGH分泌的药物。经过一夜禁食后，静脉内输注盐酸精氨酸（30克/受试者），持续30分钟，在基线以及30、60、90和120分钟采集血样进行激素测定。与Bac+组相比，Bac-组在30和60分钟时精氨酸刺激的平均血浆hGH水平（P < 0.05）以及血浆hGH峰值和总和水平（P < 0.01）均降低。Bac+组与对照组之间的血浆hGH反应无显著差异。血浆IGF-I水平可能反映组织对hGH的综合反应。对照组和Bac+组的年龄与血浆IGF-I水平之间存在显著的负相关关系，但Bac-组不存在。与Bac+组相比，Bac-组的平均血浆IGF-I水平显著降低。Bac+组与对照组之间的平均血浆IGF-I水平无显著差异。SCI与身体成分变化和代谢改变有关，而hGH - IGF - I轴活性降低可能会加剧这些变化。口服长期巴氯芬治疗似乎可逆转瘫痪和制动对hGH生理学的有害影响。
