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）与特定的结合蛋白结合。我们用Western配体印迹法研究了不同条件下的血清IGF结合蛋白（igfbp）。IGFBP-3的Western免疫印迹和IGFBP-1的RIA。正常人血清中检测到4种igfbp，分子量分别为41/38、34、30、24KD， Western配体印迹法鉴定为igfbp - 3,2,1,4。生长激素缺乏症患者血清IGFBP-3降低，肢端肥大症患者血清IGFBP-3升高。甲状腺功能减退患者IGFBP-3水平轻度升高，营养不良患者IGFBP-3水平降低，IGFBP-2水平升高。严重肝功能障碍患者所有igfbp均下降。这些数据表明血清IGFBP-3由肝脏产生，并依赖于生长激素和营养状况。在伴有低血糖（NICTH）的非胰岛细胞肿瘤患者中，血清IGFBP-2升高。2例NICTH患者成功切除肿瘤后，IGFBP-2降低，IGFBP-3升高。免疫印迹法检测血清IGFBP-3。正常人血清中IGFBP-3有3个条带，分子量分别为41,38,30kd。这三个IGFBP-3条带在肢端肥大症患者中升高，在生长激素缺乏患者中降低。孕妇血清中显示大量30KD IGFBP-3。在一些NICTH患者中，大部分IGFBP-3为30KD，在成功切除肿瘤后该条带消失。5名正常受试者分别给予0.06mg/kg或0.12mg/kg IGF-I时，RIA测定IGFBP-1在1h升高，5h达到峰值。我们报道了不同条件下的血清IGFBP。这些观察结果有助于研究IGF的生物利用度。

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.