RELATIVE ABUNDANCE AND MOLECULAR-SIZE OF IMMUNOREACTIVE INSULIN-LIKE GROWTH FACTOR-I AND FACTOR-II IN HUMAN FETAL TISSUES
RELATIVE ABUNDANCE AND MOLECULAR-SIZE OF IMMUNOREACTIVE INSULIN-LIKE GROWTH FACTOR-I AND FACTOR-II IN HUMAN FETAL TISSUES
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DOI：
10.1016/0378-3782(90)90110-5
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发表时间：
1990-01-01
影响因子：
2.5
通讯作者：
HILL, DJ
中科院分区：
文献类型：
--
作者：
HILL, DJ
以前的研究已经量化了组织的mRNA转录本，表明在人类胎儿发育过程中，IGF II的表达显著高于IGF I。然而，这还没有通过从胎儿组织中回收和定量IGF多肽来直接测试。用1M醋酸提取人胎儿组织，用酸性凝胶过滤从上清液中分离出胰岛素样生长因子(IGF)I和II免疫活性物质。当估计从Sephadex G50洗脱出来的总免疫活性IGF I或II的分子量约为6至15 kDa时，考虑到可能的血液污染，五个胎儿的组织平均含有230 fM/mg细胞DNA IGF I和690 fM/mg IGF II。IGF II/IGF I肽含量的比率从肌肉的1.6到胸腺的7.8不等。组织上清液、胎儿血浆和胎儿成纤维细胞条件培养液在Sephadex G75上的分离表明，免疫活性IGF II除7.5 kDa外，还在8~15 kDa之间洗脱。虽然胎儿组织中IGF II的免疫反应性高于IGF I，但IGF II多肽的可能存在与先前报道的IGF II的mRNA大量过剩并不一致。
Previous studies which have quantitated tissue mRNA transcripts have suggested that IGF II is expressed in substantially greater amounts than IGF I during human fetal development. However, this has not been tested directly by recovery and quantitation of IGF peptides from fetal tissues. Tissues from human fetuses were extracted in 1 M acetic acid, and insulin-like growth factor (IGF) I and II immunoreactive species separated from the supernatants by acidic gel filtration. When total immunoreactive IGF I or II eluting from Sephadex G50 between approximately 6 and 15 kDa molecular weight was estimated, allowing for likely blood contamination, tissue from five fetuses contained, on average, 230 fM/mg cell DNA IGF I and 690 fM/mg IGF II. The ratio of iGF II:IGF I peptide content varied from 1.6 in muscle to 7.8 in thyumus. Separation of tissue supernatants, fetal plasma and fetal fibroblast-conditioned culture medium on Sephadex G75 revealed that immunoreactive IGF II eluted with molecular weights between 8 and 15 KDa, in addition to 7.5 kDa. While fetal tissues contain more IGF II than IGF I immunoreactivity, the likely presence of IGF II peptide does not agree with the great excess of mRNA for IGF II reported previously.