Protein Nutrition and IGF-I and IGF-related Proteins Nutritional Regulation of Biosynthesis and Biological Action of IGF-I and IGF-related Proteins.

1)胰岛素样生长因子-I（IGF-I）和胰岛素样生长因子结合蛋白（IGFBPs）在不同生理条件下的血浆浓度和基因表达：利用这些蛋白的抗体和cDNA，我们测量了在不同生理条件下IGF-I和IGFBPs的血浆浓度和组织mRNA的量。结果表明，在蛋白质营养不良和糖尿病的情况下，IGF-I、IGFBP-3和IGFBP-4的浓度降低，而IGFBP-1和IGFBP-2的浓度升高。2）大鼠IGF-I和IGFBP-1基因的转录调控：我们克隆了大鼠IGF-I和IGFBP-1基因的5 '上游区。特别是，在IGFBP-1基因的情况下，5 '上游区的一个片段与从对照或蛋白质限制的大鼠制备的肝核提取物的不同相互作用被证实。 ...更多信息 d原代培养大鼠肝实质细胞和非实质细胞IGFBPs的产生：在肝实质细胞中，生长激素和胰岛素诱导IGF-I的产生，并且每种激素以不同的方式调节IGFBP-1和IGFBP-4的产生。另一方面，IGFBP-3的产生仅在非实质细胞中观察到，而且IGF-I刺激其产生。这些结果证明了肝中实质细胞和非实质细胞在IGF-I和IGFBP产生中的相互关系。4）IGF-1靶细胞中酪氨酸磷酸化中cAMP依赖性和IGF-1依赖性信号途径之间的相互作用：我们发现，TSH预处理FRTL-5大鼠甲状腺细胞可显著增强IGF-I的促有丝分裂反应以及TSH和IGF-I之间的协同作用。I与细胞内蛋白质酪氨酸磷酸化的变化相关。在促甲状腺激素诱导细胞产生IGF-I的过程中，cAMP依赖性酪氨酸激酶可能起重要作用。这些酪氨酸激酶的重要底物的纯化正在进行中。少

1) Plasma concentrations and gene expression of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) under various physiological conditions of rats : Using antibodies and cDNAs of these proteins, we measured the plasma concentrations and the amounts of tissues'mRNAs of IGF-I and IGFBPs under various physiological conditions. As a result, under protein malnutrition and diabetes, the concentrations of IGF-I,IGFBP-3 and IGFBP-4 decreased, however, the concentrations of IGFBP-1 and IGFBP-2 increased. Furthermore, the amounts of liver IGFBP-1 and IGFBP-2 mRNAs increased in response to protein restriction.2) Regulation of transcription of rat IGF-I and IGFBP-1 genes : We have cloned 5'upstream regions oa rat IGF-I and IGFBP-1 genes. Especially, in the case of the IGFBP-1 gene, the different interaction of one fragment of 5'upstream region and liver nuclear extract prepared from control or protein-restricted rats, was observed.3) Regulation of IGF-I an … More d IGFBPs production in primary cultured liver parenchymal and nonparenchymal cells of rats : In liver parenchymal cells, growth hormone and insulin induced IGF-I production, and each hormone regulated IGFBP-1 and IGFBP-4 production in different manners. On the other hand, the IGFBP-3 production exclusively observed in nonparenchymal cells, furthermore, IGF-I stimulated its production. These results demonstrates the interrelationship between parenchymal and nonparenchymal cells in the production of IGF-I and IGFBPs in liver.4) Interaction between cAMP-dependent and IGF-I dependent signal pathways in tyrosine phosphorylation in IGF-I-target cells : We found that pretreatment of FRTL-5 rat thyroid cells with TSH markedly potentiated the mitogenic response of IGF-I and the synergism between TSH and IGF-I was correlated with changes in tyrosine phosphorylation of intracellular proteins. In the process of priming cells to IGF-I by TSH treatment, cAMP-dependent tyrosine kinases may play important roles. Purification of important substrates of these tyrosine kinases is progressing. Less