Bell S C, Patel S R, Jackson J A, Waites G T
Department of Biochemistry, University of Leicester, Leicester Royal Infirmary.
J Endocrinol. 1988 Aug;118(2):317-28. doi: 10.1677/joe.0.1180317.
Pregnancy-associated endometrial alpha 1-globulin (alpha 1-PEG) is quantitatively the major secretory protein product, synthesized and secreted in vitro, of the human decidualized endometrium during pregnancy. This protein has been purified from cytosolic extracts of this tissue and has now been characterized as a 32 kDa somatomedin/insulin-like growth factor (IGF)-binding protein. Immunoreactive alpha 1-PEG isolated from amniotic fluid exhibited identical physiochemical properties and IGF-I-binding characteristics. In cytosolic extracts of pregnancy endometrium, in incubation medium of this tissue and in amniotic fluid, the 32 kDa protein represented the major alpha 1-PEG immunoreactive protein and major IGF-I-binding component. Purified alpha 1-PEG and incubation medium of pregnancy endometrium competed for IGF-I with placental membrane IGF receptors in vitro. The implications of the endometrial source of IGF-I-binding protein are discussed with reference to the origin of the amniotic fluid and serum small Mr IGF-binding protein and to the suggested paracrine effect upon trophoblast proliferation.
妊娠相关子宫内膜α1球蛋白（α1-PEG）是孕期人蜕膜化子宫内膜在体外合成并分泌的主要分泌蛋白产物。该蛋白已从该组织的胞质提取物中纯化出来，现已被鉴定为一种32 kDa的生长调节素/胰岛素样生长因子（IGF）结合蛋白。从羊水分离出的免疫反应性α1-PEG表现出相同的理化性质和IGF-I结合特性。在妊娠子宫内膜的胞质提取物、该组织的培养液以及羊水中，32 kDa蛋白是主要的α1-PEG免疫反应性蛋白和主要的IGF-I结合成分。纯化的α1-PEG和妊娠子宫内膜培养液在体外与胎盘膜IGF受体竞争IGF-I。本文参照羊水和血清中小分子量IGF结合蛋白的来源以及对滋养层细胞增殖的旁分泌作用，讨论了IGF结合蛋白的子宫内膜来源的意义。
