Effects of Insulin-Like Growth Factor I in Man

ABSTRACT. A 6-day period of subcutaneous infusion with recombinant human insulin-like growth factor I in three healthy male volunteers resulted in an increase in the ratio of insulin to C-peptide levels and significant decreases in triglyceride levels and the ratio of total to high density lipoprotein—cholesterol in serum. Increased renal plasma flow and glomerular filtration rates were also observed.     

甲状腺功能减退症患儿血清生长激素、胰岛素样生长因子-Ⅰ、胰岛素样生长因子结合蛋白-3水平的变化

目的通过监测甲状腺功能减退症患儿生长激素(GH)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、胰岛素样生长因子结合蛋白-3(IGFBP-3)水平变化,探讨甲状腺功能减退症患儿GH-IGF轴与甲状腺素的变化规律。方法对56例甲状腺功能减退症(14例先天性甲状腺功能减退症和32例桥本病)患儿治疗前后血GH、IGF-Ⅰ、IGFBP-3水平和50例健康儿童血GH、IGF-Ⅰ、IGFBP-3水平进行监测。结果先天性甲状腺功能减退症新生儿9例患儿IGF-Ⅰ、IGFBP-3水平显著降低,经治疗后甲状腺功能逐渐恢复正常;5例先天性甲状腺功能减退症患儿和32例桥本病患儿无显著变化。结论先天性甲状腺功能减退症患儿存在GH-IGF轴功能紊乱,是导致身材矮小的重要原因,早期予甲状腺素治疗有利于维持患儿正常生长发育。     

Secretion of a Large Molecular-Weight Form of Insulin-Like Growth Factor by a Primary Renal Tumor

A 5-year-old boy with an abdominal mass was found to have a primary renal tumor of poorly identifiable histology. Prior to resection of the tumor, the patient exhibited several episodes of biochemical hypoglycemia. The hypoglycemia did not recur after operation. Analysis of tumor tissue and of pre- and post-operative sera by column chromatography showed elevated insulin-like growth factor II (IGF-II) levels in the tumor; an abnormal large-molecular weight precursor form of IGF-II (pro-IGF-II) comprised 53% of total IGF-II in the tumor and 42% in preoperative serum. No pro-IGF-II was found in the serum 6 weeks post-operatively. Abnormal IGF-II secreted by the tumor may have mediated the hypoglycemia seen prior to tumor resection. This pediatric renal tumor is the first to our knowledge for which an association of non-islet cell tumor-related hypoglycemia and elevated tumor IGF-II content has been described. © 1995 Wi1ey-Liss, Inc.     

血清胰岛素样生长因子-1、胰岛素样生长因子结合蛋白-3在矮小症儿童诊断和疗效判断中的价值

目的探讨胰岛素样生长因子-1（IGF-1）及其结合蛋白-3（IGFBP-3）在矮小症儿童诊断及疗效判断中的价值。方法1．对124例青春发育前矮小症患儿用精氨酸激发试验和可乐定激发试验检测其血清生长激素（GH）水平，并根据患儿GH峰值分为生长激素缺乏组（GHD组，40例）、特发性矮小组（1SS组，84例）。选取20例健康儿童作为健康对照组。对所有儿童采用酶联免疫吸附法检测血清IGF—1和IGFBP-3。对GHD组、ISS组和健康对照组儿童血清IGF-1和IGFBP-3水平进行两两比较。2．对15例GHD和30例ISS患儿予国产重组人生长激素（rhGH）0．1IU／（kg·d）治疗6个月，于治疗前及治疗6个月分别测定其身高、体质量、骨龄及血清IGF-1、IGFBP-3，并进行治疗前后的对照。结果1．GHD组和ISS组患儿血清IGF-1和IGFBP-3水平明显低于健康对照组（Pa〈0．01），GHD组与ISS组患儿血清IGF-1和IGFBP-3水平比较均有显著差异（Pa〈0．01），GHD组患儿治疗前后血清IGF-1、IGFBP-3比较有显著差异（Pa〈0．01）；诊断GHD，IGF-1的特异性为67．8％，敏感性为75％；IGFBP-3的特异性为88％，敏感性为85％。2．rhGH治疗后身高增长速度明显加快，血清IGF-1、IGFBP-3水平显著升高；治疗前血清IGF-1与治疗6个月生长速度呈显著负相关（r=-0．78P〈0．01）；治疗6个月后IGF-1的变化与治疗后生长速度呈显著正相关（r=0．82P〈0．01）。结论IGF-1、IGFBP-3可用于儿童矮小症的诊断及疗效评价。     

Comparative Immunohistochemical Study of Insulin-like Growth Factor II and Insulin-like Growth Factor ReceptorType 1 in Pediatric Brain Tumors

Insulin-like growth factor (IGF)-II is an important growth factor in development of the central nervous system. The purpose of this study was to evaluate expression of IGF-II and IGF receptor type 1 (IGFR1) in various pediatric brain tumors. Immunohistochemistry for IGF-II and IGFR1 was performed on 15 choroid plexus papillomas (CPPs) including 1 atypical CPP, 2 choroid plexus carcinomas (CPCs), 5 anaplastic ependymomas, 7 nonanaplastic ependymomas (simply referred to as “ependymoma”), 5 medulloblastomas, 1 cerebral neuroblastoma, and 1 atypical teratoid/rhabdoid tumor (ATRT) along with 10 non-neoplastic choroid plexus and 3 non-neoplastic ependymal linings. All non-neoplastic choroid plexus, CPPs, CPCs, anaplastic ependymomas, ATRT, 71% of ependymomas, and 67% of non-neoplastic ependymal linings showed cytoplasmic positivity for IGF-II, whereas all medulloblastomas and the cerebral neuroblastoma were negative for IGF-II. In addition to cytoplasmic positivity for IGFR1, membranous positivity was observed in 73% of CPPs, both CPCs, the ATRT, 22% of non-neoplastic choroid plexus, 80% of anaplastic ependymomas, and 29% of ependymomas, but not in any medulloblastoma, cerebral neuroblastoma, or non-neoplastic ependymal lining. IGF-II and IGFR1 may play roles in the pathogeneses of CPP, CPC, anaplastic ependymoma, ependymoma, and ATRT. Immunohistochemical testing for IGF-II and IGFR1 may be useful in differentiating ATRT, CPC, and anaplastic ependymoma from medulloblastoma and cerebral neuroblastoma. Received June 23, 1999; accepted September 30, 1999.     

Anabolic and Tissue Repair Functions of Recombinant Insulin-Like Growth Factor I

ABSTRACT. Recombinant human insulin-like growth factor I (rhIGF-I) has been produced in yeast and purified using conventional biochemical techniques. It has been shown to have receptor-binding properties and in vitro growth-promoting activities comparable to those of plasma-derived IGF-I. The anabolic actions of IGF-I can be studied using both systemic and local administration in vivo. The growth-promoting activity and systemic anabolic actions of recombinant IGF-I were studied in mutant dwarf rats. IGF-I was infused intravenously for 9 days and resulted in a significant gain in body weight and significant bone growth, though the effects were not as great as those observed with human growth hormone (hGH). IGF-I also had selective effects on specific organs which were not observed in hGH-treated animals. The results indicate that the growth-promoting effects of IGF-I show a different pattern compared to hGH. The effects of local administration of recombinant IGF-I on tissue regeneration and maintenance were also studied in hypophysectomized and normal rats. After hypophysectomy, the regeneration processes were impaired when both peripheral nerve regeneration and incision wound healing were considered. The results indicate that local administration could have significant effects on regeneration of, for example, peripheral nerves.     

Effects of insulin-like growth factor I treatment on the molecular distribution of insulin-like growth factors among different binding proteins

The molecular distribution of insulin-like growth factor I (IGF-I) and IGF-II among the IGF binding proteins (IGFBPs) was studied before and during IGF-I therapy in Ecuadorean adults with growth hormone receptor deficiency (GHRD). Of the total circulating IGF-I and IGF-II, 70% was carried by the 150 kDa complex in normal subjects, while in patients with GHRD, 50% of serum IGF-I, but only 30–35% of serum IGF-II, was measured within the 150 kDa IGFBP-3 region. Administration of IGF-I altered the concentration of IGF-I and IGF-II, although the percentage of total IGF measured within each IGFBP region was not affected, as the increase in IGF-I and the decrease in IGF-II were proportional. Similarly, serum concentrations of IGFBP-3 and the acid-labile subunit, measured by radioimmunoassay, were unaltered. Thus, administration of IGF-I to patients with GHRD was unable to correct the aberrant distribution of IGFs among the IGFBPs.     

胰岛素样生长因子-1受体基因与特发性矮小相关性研究进展

生长激素-胰岛素样生长因子(GH-IGF)轴是调节儿童生长发育中最重要的神经内分泌轴.胰岛素样生长因子-1受体( IGF-1 R)是调节该轴的激素受体级联反应的效应分子,它的分子结构或功能异常,将影响靶基因IGF-1与其结合,从而引起生长障碍,可能与特发性矮小(ISS)发生有一定关系.国内外尚无IGF-1R基因与ISS的研究,为探讨其与ISS的关系,现就近年来有关IGF-1 R与人体生长障碍的研究作简要综述.     

Insulin-like growth factors in lysosomal storage disease

Recent data indicate that insulin-like growth factor II (IGF II) and lysosomal enzymes bind to a common receptor. We measured serum IGF I and II levels in 16 patients with various lysosomal storage disorders. The IGF serum concentrations were normal as long as no marked liver disease was present. Under these conditions no direct interconnection between the lysosomal system and the serum IGF levels was found.     

Insulin-Like Growth Factors (IGFs) and IGF Binding Proteins in Chronic Renal Failure: Evidence for Reduced Secretion of IGFs

To test the hypothesis that growth hormone (GH) insensitivity is responsible, amongst other mechanisms, for impaired growth in uraemic children, insulin-like growth factor I (IGF-I), IGF-II, IGF binding protein-1 (1GFBP-1), IGFBP-2 and IGFBP-3 were measured by radioimmunoassay in normal control children, in patients with end-stage renal failure (n = 51) and in patients with preterminal chronic renal failure (n = 11) and the production rate of IGF was calculated. A unique pattern of normal IGF-I and IGF-II levels and markedly increased levels of all three IGFBPs was present in uraemia. Measurement of free IGF-II binding capacity, and affinity cross-linking experiments showed that the excess immuno-reactive IGFBP was able to bind IGFs. To explain the excess of unoccupied IGF binding sites in uraemia, a mathematical model was developed which describes the production of IGFs and their interaction with IGFBP. Calculations of IGF secretion rates suggested that production of IGF is two orders of magnitude lower in uraemic children than in control children, despite normal GH secretion. It is concluded that in uraemia there is a relative GH insensitivity with respect to IGF production.     

腺病毒介导胰岛素样生长因子-1基因对链脲佐菌素诱发1型糖尿病大鼠的保护作用

目的观察腺病毒介导胰岛素样生长因子-1(IGF-1)基因对链脲佐菌素(STZ)诱导SD大鼠1型糖尿病(T1DM)的预防保护作用,比较肌肉注射、腹腔注射及胰腺被膜下注射3种不同注射途径的效果。方法4～6周龄SD雄性大鼠90只,随机分为糖尿病对照组(A组)、空白对照组(B组)、腺病毒空载体对照组(C组)、肌肉注射含有IGF-1基因的重组腺病毒(Ad-rIGF-1)组(D组)、腹腔注射Ad-rIGF-1组(E组)、胰腺被膜下注射Ad-rIGF-1组(F组),每组各15只。A组、B组不做任何处理,C组注射含空载体(Ad-eGFP)的重组腺病毒液0.1mL,D组、E组、F组注射含Ad-rIGF-1的重组腺病毒液0.1mL。1周后,A组、D组、E组及F组腹腔注射STZ50mg.kg-1诱发糖尿病,每周测定体质量、血糖。5周后,处死大鼠,取其胰腺做病理切片及免疫组织化学法观察胰腺炎症浸润程度和IGF-1局部表达程度;取下腔静脉血,测定IGF-1和胰岛素水平。结果D组、E组、F组与A组比较,糖尿病发病率低,平均血糖水平低,但血糖水平明显高于B组和C组。胰腺切片HE染色显示D组、E组、F组胰腺炎症浸润程度较A组轻,但明显重于B...     

人胰岛素样生长因子1基因质粒载体的构建及其在人脐血源性神经干细胞中的表达

目的 构建人胰岛素样生长因子1(IGF-1)质粒表达载体,并观察重组体pcDNA3.1-IGF-1转染后的脐血源性神经干细胞(NSCs)中IGF-1基因的表达情况.方法 通过反转录-PCR(RT-PCR)方法从胎肝中提取IGF-1基因,胶回收方法分别纯化PCR产物(IGF-1基因)和质粒pcDNA3.1,二者分别由DNA限制性内切酶BamH Ⅰ与 Hind Ⅲ双酶切后,经T4 DNA Ligase连接的方法将IGF-1基因克隆到质粒表达载体pcDNA3.1中,采用测序方法及DNA限制性内切酶BamH Ⅰ与 Hind Ⅲ双酶切方法鉴定重组质粒,脂质体转染法将重组体pcDNA3.1-IGF-1及空质粒pcDNA3.1分别转染至脐血源性NSCs内,经G418抗性筛选后,利用免疫细胞化学法和RT-PCR法检测IGF-1基因在基因转染脐血源性NSCs内的表达情况.结果 IGF-1基因从胎肝中成功提取.重组体pcDNA3.1-IGF-1经基因测序及DNA限制性内切酶BamH Ⅰ与 Hind Ⅲ双酶切证实质粒表达载体pcDNA3.1-IGF-1构建正确.重组体经脂质体法转染脐血源性NSCs 24 h后,经G418筛选2周得到细胞抗性克隆,免疫细胞化学法检测到IGF-1基因在重组质粒表达载体pcDNA3.1-IGF-1转染的脐血源性NSCs中成功表达.RT-PCR方法检测到重组质粒pcDNA3.1-IGF-1转染的脐血源性NSCs中IGF-1 mRNA表达阳性,而空质粒pcDNA3.1转染的脐血源性NSCs中IGF-1 mRNA表达阴性.结论 IGF-1基因可在重组质粒表达载体pcDNA3.1-IGF-1转染的脐血源性NSCs内成功表达.     

生长激素缺乏儿童血清胰岛素样生长因子-1和瘦素水平的变化及其相互关系

目的探讨生长激素缺乏(GHD)儿童血清胰岛素样生长因子1(IGF1)、瘦素水平的变化。方法用放射免疫法分别检测20例正常青春期前儿童和23例GHD患儿血清IGF1和瘦素的水平。结果GHD组血清IGF1水平(51.158±29.988)μg/L低于对照组(112.680±41.540)μg/L,两者有显著差异(t=5.619P<0.01);瘦素水平(6.002±2.204)μg/L高于对照组(4.523±2.204)μg/L,两者比较有显著差异(t=2.225P<0.05);但IGF1和瘦素之间无相关性(P>0.05)。结论IGF1和瘦素对GHD患儿生长发育的调节作用是相互独立的。     

Serum Levels of Free Insulin-Like Growth Factor (IGF)-I in Normal Children

Serum levels of free insulin-like growth factor (IGF)-I were measured by immunoradiometric assay (IRMA) in fasting sera of 137 normal boys and 120 normal girls aged from 8 to 15 yr to study relationships between free IGF-I levels and ages, total IGF-I, IGF binding protein (IGFBP)-1, IGFBP-3, and acid-labile subunit (ALS) levels. In both sexes, serum free IGF-I levels and the ratios of free IGF-I to total IGF-I were significantly higher in the pubertal age groups than in the prepubertal age groups. Serum levels of free IGF-I showed a significant positive correlation with those of total IGF-I, IGFBP-3 and ALS, while they showed a significant negative correlation with those of IGFBP-1. These observations suggest that increase in serum free IGF-I levels during puberty is caused by a dramatic increase in total IGF-I, rather than IGFBP-3, and a decrease in IGFBP-1. Also, high free IGF-I levels may play an important role in pubertal growth spurt.     

胰岛素样因子3对体外培养的小鼠睾丸引带细胞增殖和收缩活性的影响

目的 探讨胰岛素样因子3 (INSL3)对体外培养的小鼠睾丸引带细胞增殖和收缩活性的影响.方法 手术放大镜解剖出3日龄雄性昆明小鼠的睾丸引带组织,进行原代细胞培养后传代.将传代细胞随机分为正常对照组和实验组,实验组加入INSL3,浓度分别为3.3×10-3 μmol·L-1、3.3×10-4 μmol·L-1、3.3×10-5 μmol·L-及3.3 × 10-6 μmol·L-1,分别持续作用12 h、24h、48 h,利用细胞计数试剂盒(CCK-8)检测其细胞增殖情况;细胞免疫荧光和流式细胞术检测其细胞纤维状肌动蛋白(F-actin)的结构变化及表达情况.结果 不同浓度INSL3作用后的不同时间点,检测细胞增殖和收缩活性的相关指标,结果均存在时间-剂量效应,且差异有统计学意义(p＜0.05).正常对照组及各实验组细胞均呈持续性增殖,24h后增殖更明显.与正常对照组比较,INSL3可刺激睾丸引带细胞骨架重塑,细胞周边肌动蛋白丝带增多,胞质中微丝F-actin明显粗大、变长,细胞中F-actin表达量增加.各实验组中以3.3 ×10-3 μmol·L-1组变化尤其明显.结论 INSL3对睾丸引带细胞增殖和收缩活性有直接促进作用,可能参与睾丸引带发育甚或睾丸下降过程的调节.     

Effects of Short-Term Growth Hormone Therapy in Short Children without Growth Hormone Deficiency

ABSTRACT. Evaluation of 24-hour endogenous growth hormone (GH) secretion was carried out in 62 children, aged 7-16 years, who did not have classic GH deficiency (GHD). The mean 24-hour GH concentration, determined at 20-minute intervals over 24 hours, was variable, ranging from 1.28 to 11.39 μg/l with a mean of 4.95 ± 2.55 μl (± SD). There was a positive correlation between mean 24-hour GH concentration and plasma insulin-like growth factor I (IGF-I) values ( r = 0.54; p < 0.01). Recombinant human GH, 0.1 IU/kg/day was administered to 30 of the 62 children for 6 months followed by 6 months'observation without treatment. Thereafter, GH was administered at the same dose for a further 6 months to 16 children. The mean height velocities before, during, and after the first treatment period were 4.3 ± 0.9, 7.3 ± 1.9 and 4.9 ± 2.0 cm/year (mean ± SD), respectively. The height velocity during treatment was greater than pre- and post-treatment values ( p < 0.001). The height velocity Increased again during the second treatment period to a mean of 8.5 ± 2.0 cm/year ( p < 0.001). Nine other children were treated continuously in a similar manner for 1 year and their height velocity increased significantly from 4.1 ± 1.4 to 6.0 ± 1.9 cm/year ( p < 0.001). According to our criteria, 29 of the 39 children (74.4%) who were treated for 6-12 months showed a GH-dependent height increase during therapy. There were no differences between the children who responded to GH treatment and those who did not in terms of Chronological age, bone age, plasma IGF-I level, maximal GH level to insulin-induced hypoglycaemia, or mean 24-hour plasma GH concentration. These data indicate that some short children without GHD respond to GH treatment with an increased height velocity. Further investigations are required to determine the effect of GH on final height.     

Growth Hormone and Insulin-Like Growth Factor I: Nutritional Pathophysiology and Therapeutic Potential

The growth hormone—insulin-like growth factor I axis has been appreciated for more than 30 years and the effects of malnutrition on this axis for more than 20 years. Over the last decade, advances in molecular biology have permitted enhanced understanding of feedback regulation between growth hormone and IGF-I at the gene level, including limited information on nutritional influences. Similarly, the availability of recombinant human growth hormone has allowed controlled clinical studies demonstrating its net anabolic actions at hypocaloric dietary energy intake levels and its ability to enhance height velocity in children with various causes of diminished growth. Although investigational use of recombinant IGF-I in humans has been limited, its actions are likely to complement those of growth hormone during periods of profound dietary energy deficit. From the information presented, two hypotheses are developed. First, recombinant IGF-I administration will enhance substrate anabolic events during the acutely malnourished state when dietary intake is severely limited. Second, administration of recombinant human growth hormone will accelerate protein anabolism and catch-up growth during the period of recovery from protein-energy malnutrition. Given current clinical investigational tools and the availability of both recombinantly-produced hormones, these are testable hypotheses.     

胰岛素样生长因子结合蛋白2在新生鼠肺发育中的作用

目的探索胰岛素样生长因子结合蛋白(IGFBP)2在新生鼠肺发育中的作用。方法SD孕鼠80只分为4组,即A:对照组;B:地塞米松(Dex)1组;C:Dex2组;D:维A酸(RA)组。A、B、D组分别于孕18～20d皮下注射生理盐水、Dex,腹腔注射RA;C组于生后1～3d皮下注射Dex。各组分别于孕18、20、21d(C组孕期不取)、生后1、3、5、7、10、14、21d取肺标本作形态学检查、免疫组织化学、Westernblot及RT PCR检测。结果1.肺组织形态学:B、C组早期肺泡发育提前,数目多,壁薄,晚期则明显落后于A、D组。2.IGFBP2肺表达:A组中IGFBP2主要在胎肺组织中表达,孕18d左右表达最强,随后表达渐减弱。B、C组表达趋势同A组,但生后各时间点均较A组增强;D组生后各时间点均较A组减弱。3.Westernblot:IGFBP2多肽表达强度各组孕18d表达最强,随后渐降低;B、C组生后各时间点表达强度明显高于A组(P均<0.01);D组各时间点浓度均明显低于A组(P均<0.01)。4.RT PCR:IGFBP2mRNA表达的强度变化规律与其肽浓度变化相似。结论IGFBP2在肺发育过程起重要作用,其浓度过高则影响肺发育。     

神经生长因子受体在先天性巨结肠表达的意义

目的 探讨神经生长因子受体（ＮＧＦＲ）在先天性巨结肠（ＨＤ）中的分布情况及其意义。方法 应用ＮＧＦＲ免疫组化方法对１０例３周￣２岁的ＨＤ患儿及８例对照组患儿结肠进行染色观察。结果 丰富的ＮＧＦＲ染色阳性神经纤维分布于正常结肠环肌层及粘膜下层,少量分布于纵肌层,ＮＧＦＲ染色阳性神经元分布于肌间神经丛及粘膜下神经丛;ＮＧＦＲ染色阳性神经纤维在ＨＤ无肌间神经节细胞肠段肌层及粘膜下层内明显减少或缺如,而肌