Maternal and neonatal somatomedin C/insulin-like growth factor-I (IGF-I) and IGF binding proteins during early lactation in the pig.
Maternal and neonatal somatomedin C/insulin-like growth factor-I (IGF-I) and IGF binding proteins during early lactation in the pig.
复制标题
猪泌乳早期的母体和新生儿生长调节素 C/胰岛素样生长因子-I (IGF-I) 和 IGF 结合蛋白。
DOI：
10.1016/0012-1606(88)90409-5
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发表时间：
1988
影响因子：
2.7
通讯作者：
Reinhart,G
中科院分区：
文献类型：
--
作者：
Simmen,FA;Simmen,RC;Reinhart,G
用Tris中和的猪、牛、羊和人乳腺分泌物的酸性乙醇提取物以及猪母血和新生儿血清进行胰岛素样生长因子-I（IGF-I）的RIA。所有三种动物的初乳中均存在高水平（50-500 ng/ml）的免疫反应性IGF-I。在猪乳汁中也发现了IGF-I，但其水平相对于初乳降低了10- 100倍。母体（猪）血清的特点是IGF-I浓度介于初乳和乳汁之间。新生猪血清中IGF-I水平相对较低，在出生后第3天和第7天之间增加约1.4倍。在非变性凝胶过滤柱中对猪初乳进行分级分离，证明内源性IGF-I与两种主要结合蛋白（复合物的Mr为150，000和50，000）相关。还观察到第三种免疫反应性组分在色谱柱空隙体积分数（Mr> 158，000）中出现。150，000和50，000 Mr复合物也存在于足月母猪的血清中。相反，猪乳汁中IGF-I的免疫反应性仅局限于150，000 Mr复合物中。用125 I-IGF-I孵育猪初乳和牛奶，显示一个明显的、未占据的IGF结合蛋白，对应于150，000 Mr复合物的结合蛋白，而从足月母猪获得的血清显示150，000和50，000 Mr未占据的结合蛋白。从出生后立即获得的猪新生儿血清（合并）的分级显示IGF-I免疫反应性的异质性模式，包括150，000和50，000 Mr形式。在此色谱模式的定性差异是明显的，在出生后6小时的血清中，并在摄入初乳发生。新生猪血清中未被占据的IGF结合蛋白仅为小分子类。这些结果表明，乳腺分泌的IGF-I及其结合蛋白的时间调节期间立即分娩。出生后早期血清IGF-I谱的生理变化可能部分反映了新生儿对母体IGF-I的吸收和/或反应。
RIA for insulin-like growth factor-I (IGF-I) was performed on Tris-neutralized, acid-ethanol extracts of porcine, bovine, ovine and human mammary secretions, and porcine maternal and neonatal sera. High levels (50–500 ng/ml) of immunoreactive IGF-I were present in the colostrum of all three animal species. IGF-I was also identified in porcine milk, though at levels 10- to 100-fold reduced relative to that in colostrum. Maternal (pig) sera was characterized by IGF-I concentrations intermediate between that in colostrum and that in milk. IGF-I levels were relatively low in serum of newborn pigs and exhibited an approximately 1.4-fold increase between Days 3 and 7 of postnatal life. Fractionation of pig colostrum in nondenaturing, gel-filtration columns demonstrated association of endogenous IGF-I with two prominent binding proteins (Mr's of 150,000 and 50,000 for the complexes). A third immunoreactive component was also observed to elute in the column void volume fractions (Mr> 158,000). The 150,000 and 50,000Mrcomplexes were also present in serum obtained from sows at term. In contrast, IGF-I immunoreactivity in porcine milk was localized exclusively in the 150,000Mrcomplex. Incubation of porcine colostrum and milk with125I-IGF-I revealed a prominent, unoccupied IGF binding protein corresponding to that of the 150,000Mrcomplex, whereas serum obtained from sows at term displayed both the 150,000 and 50,000Mrunoccupied forms. Fractionation of (pooled) serum obtained from porcine neonates immediately at birth revealed a heterogeneous pattern of IGF-I immunoreactivity which included both the 150,000 and 50,000Mrforms. Qualitative differences in this chromatographic pattern were apparent in serum at 6 hr postnatal and after ingestion of colostrum had occurred. The unoccupied IGF binding proteins in newborn pig serum were solely of the small size class. These results demonstrate that mammary secretion of IGF-I and its binding proteins are temporally regulated during the period immediately surrounding parturition. Physiologic alterations in the serum IGF-I profile during early postnatal life may reflect in part the uptake and/or response of the neonate to maternal IGF-I.