pathophysiological significance of insulin-like growth factor binding protein

血清和组织中的胰岛素样生长因子（IGF）与特异性结合蛋白结合。我们使用Western配体印迹法研究了不同条件下血清IGF结合蛋白（IGFBPs）。正常人血清中IGFBP-3的蛋白质免疫印迹和IGFBP-1的放射免疫分析结果表明，正常人血清中存在4种IGFBP-3，2，1，4，分子量分别为41/38，34，30，24 KD。血清IGFBP-3在GH缺乏患者中降低，在肢端肥大症患者中升高。甲减患者IGFBP-3轻度升高，营养不良患者IGFBP-3降低，IGFBP-2升高。所有IGFBPs在严重肝功能障碍患者中均降低。这些数据表明，血清IGFBP-3由肝脏产生，并取决于GH和营养状态。在非胰岛细胞肿瘤伴低血糖（NICTH）患者中，血清IGFBP-2升高。两例NICTH患者在肿瘤成功切除后，IGFBP-2降低，IGFBP-3升高。正常人血清IGFBP-3有3条带，分子量分别为41、38、30 KD。IGFBP-3的这三条带在肢端肥大症患者中升高，在GH缺乏症患者中降低。孕妇血清中有大量30 KD IGFBP-3。部分NICTH患者IGFBP-3以30 KD为主，肿瘤切除后IGFBP-3条带消失，5名正常人分别给予0.06mg/kg或0.12mg/kg IGF-I后，IGFBP-1于1h升高，5 h达高峰。这些观察结果对于研究IGF生物利用度是有用的。

Insulin-like growth factor(IGF)in serum and tissue binds to specific binding proteins. We investigated serum IGF binding proteins(IGFBPs)in various conditions using Western ligand blotting., Western immunoblotting of IGFBP-3 and RIA of IGFBP-1.Serum from normal subjects revealed four IGFBPs with mol wts of 41/38, 34, 30, 24KD identified as IGFBP-3, 2, 1, 4 using Western ligand blotting. Serum IGFBP-3 decreased in the patients with GH deficiency and increased in acromegalic patients. IGFBP-3 sightly increased in patients with hypothyroidism and IGFBP-3 decreased and IGFBP-2 increased in malnutrition. All IGFBPs decreased in patients with severe liver dysfunction. These data show that serum IGFBP-3 was produced from liver and depends on GH and nutritional state. In patients with nonislet cell tumor associated with hypoglycemia(NICTH), serum IGFBP-2 increased. In two patients with NICTH IGFBP-2 decreased and IGFBP-3 increased after successful tumor resection.Serum IGFBP-3 was also studied using Western immunoblotting. Serum from normal subjects revealed three bands of IGFBP-3 with mol wts of 41, 38, 30KD. These three bands of IGFBP-3 increased in acromegalic patients and decreased in patients with GH deficiency. Serum in pregnant wemen shows a large amount of 30KD IGFBP-3. In some patients with NICTH most of all IGFBP-3 was 30KD and this band disappeared after successful tumor resection.When 0.06mg/kg or 0.12mg/kg IGF-I was administered to 5 normal subjects, IGFBP-1, which was measured using RIA, increased at 1h and reached the peak at 5hs.We reported serum IGFBP in various conditions. These observations are useful for studying IGF bioavailability.