Laron Z, Klinger B, Blum W F, Silbergeld A, Ranke M B
Institute of Pediatric and Adolescent Endocrinology, Children's Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
Clin Endocrinol (Oxf). 1992 Mar;36(3):301-4. doi: 10.1111/j.1365-2265.1992.tb01449.x.
The aim of the study was to investigate the serum levels of IGFBP-3, the major IGF-I binding protein, in patients with Laron type dwarfism (LTD) before and after IGF-I treatment.
Eight Laron type dwarfism patients (four children and four adults) were treated for 7 days by one daily s.c. injection of biosynthetic IGF-I in doses of 120 or 150 micrograms/kg/day.
Blood was sampled in the fasting state before and 1 and 7 days after the last injection.
It was found that IGF-I administration significantly reduced plasma hGH levels with recovery after one week of no treatment. Serum IGFBP-3 was abnormally low (0.70 +/- 0.37 mg/l) and decreased significantly further during IGF-I treatment (to 0.48 +/- 0.28 mg/l) (P less than 0.065).
The finding that serum IGFBP-3 is low in Laron type dwarfism, a disease due to molecular defects in the GH receptor, is compatible with the hypothesis that this IGF binding protein is GH-dependent. On the other hand the decrease during IGF-I administration and concomitant suppression of GH secretion may denote either that GH activity is not completely blocked in this syndrome or that there are additional mechanisms regulating IGFBP-3 synthesis.
本研究旨在调查拉伦型侏儒症（LTD）患者在接受胰岛素样生长因子-Ⅰ（IGF-Ⅰ）治疗前后，血清中主要的IGF-Ⅰ结合蛋白IGFBP-3的水平。
8例拉伦型侏儒症患者（4名儿童和4名成人）接受每日1次皮下注射生物合成IGF-Ⅰ治疗，剂量为120或150微克/千克/天，持续7天。
在末次注射前的空腹状态以及末次注射后1天和7天采集血样。
发现给予IGF-Ⅰ后血浆人生长激素（hGH）水平显著降低，在停止治疗1周后恢复。血清IGFBP-3异常低（0.70±0.37毫克/升），在IGF-Ⅰ治疗期间进一步显著降低（至0.48±0.28毫克/升）（P<0.065）。
拉伦型侏儒症是一种由于生长激素（GH）受体分子缺陷导致的疾病，其血清IGFBP-3水平较低这一发现，与该IGF结合蛋白依赖于GH的假说相符。另一方面，在给予IGF-Ⅰ期间其水平下降以及同时出现的GH分泌受抑制，可能表明在该综合征中GH活性并未被完全阻断，或者存在调节IGFBP-3合成的其他机制。
