Developmental patterns of insulin-like growth factor-I and -II synthesis and regulation in rat fibroblasts
Developmental patterns of insulin-like growth factor-I and -II synthesis and regulation in rat fibroblasts
复制标题
大鼠成纤维细胞中胰岛素样生长因子-I和-II合成和调节的发育模式
作者：
S. O. Adams;S. Nissley;S. Handwerger;M. Rechler
胰岛素样生长因子-I（IGF-I）和IGF-II是具有相关受体特异性和体外生物活性的化学相似多肽1。IGF-I和IGF-II具有62%的氨基酸序列同一性，并且与人胰岛素原的A和B结构域具有38-48%的同源性。它们可以通过特定的放射免疫测定来区分，似乎具有不同的激素调节模式，并且可能具有不同的体内生物学功能。血浆IGF-I水平反映了垂体生长激素（GH）的循环浓度，外源性IGF-I替代GH诱导GH缺乏大鼠的躯体和骨骼生长2。最近在大鼠中的一些观察表明IGF-II在胎儿生长中可能起作用。胎鼠血清中的IGF-II水平比母体血清高20至100倍，并在出生后几天内下降3。IGF-I表现出相互的发育模式--我们最近证实培养的大鼠胚胎成纤维细胞合成大量的增殖刺激活性（MSA或rIGF-II），人IGF-II 7的大鼠同系物。我们现在证明，从大鼠2至50日龄的成纤维细胞培养物模拟从IGF-II到IGF-I生产在血清中观察到的发育开关。此外，我们发现，胎盘催乳素（PL），但不是GH刺激IGF-II在胎儿成纤维细胞的合成。相比之下，GH和PL都刺激老年大鼠成纤维细胞中IGF-I的合成，而对IGF-II的合成没有影响。PL刺激胎儿成纤维细胞IGF-II的合成提供了PL调节胎儿生长的机制。
Insulin-like growth factor-I (IGF-I) and IGF-II are chemically similar polypeptides with related receptor specificity and in vitro biological activity1. IGF-I and IGF-II have a 62% amino acid sequence identity and are 38–48% homologous with the A and B domains of human proinsulin. They can be distinguished by specific radioimmunoassays, appear to have different patterns of hormonal regulation, and presumably serve different in vivo biological functions. Plasma IGF-I levels reflect circulating concentrations of pituitary growth hormone (GH), and exogenous IGF-I substitutes for GH in inducing somatic and skeletal growth in GH-deficient rats2. Several recent observations in rats have suggested a possible role for IGF-II in fetal growth. IGF-II levels are 20- to 100-fold higher in fetal rat serum than in maternal serum and decline within days after birth3. IGF-I exhibits the reciprocal developmental pattern—low in the early neonate, rising to adult levels by approximately 4 weeks of age4,5. We recently reported6 that cultured rat embryo fibroblasts synthesize large amounts of multiplication-stimulating activity (MSA or rIGF-II), the rat homologue of human IGF-II7. We now demonstrate that fibroblast cultures established from rats 2 to 50 days of age mimic the developmental switch from IGF-II to IGF-I production observed in serum. In addition, we show that placental lactogen (PL) but not GH stimulates IGF-II synthesis in fetal fibroblasts. By contrast, both GH and PL stimulate IGF-I synthesis in fibroblasts from older rats with no effect on IGF-II synthesis. Stimulation of IGF-II synthesis in fetal fibroblasts by PL provides a mechanism whereby PL may regulate fetal growth.
培养的人成纤维细胞产生免疫反应性生长调节素的激素控制。
DOI：
10.1172/jci110001
发表时间：
1981
期刊：
The Journal of clinical investigation
影响因子：
--
作者：
Clemmons,DR;Underwood,LE;VanWyk,JJ
通讯作者：
VanWyk,JJ
胎盘催乳素、生长激素和催乳素对围产期大鼠肝脏鸟氨酸脱羧酶活性的差异影响。
影响因子：
6.1
作者：
Hurley,TW;Kuhn,CM;Schanberg,SM;Handwerger,S
通讯作者：
Handwerger,S