Chaiken R L, Moses A C, Usher P, Flier J S
J Clin Endocrinol Metab. 1986 Nov;63(5):1181-5. doi: 10.1210/jcem-63-5-1181.
A monoclonal antibody to the human type I insulin-like growth factor (IGF-I) receptor (alpha IR-3) was used to distinguish actions of insulin and IGF-I that are mediated through insulin as opposed to IGF-I receptors on human skin fibroblasts. Both insulin and IGF-I stimulate uptake of the nonmetabolized alanine analog alpha-aminoisobutyric acid (AIB) in these cells. alpha IR-3 inhibited AIB uptake stimulated by both of these hormones in a dose-dependent manner. However, the pattern of hormone action in the presence of alpha IR-3 differed for the two hormones. In the case of IGF-I, alpha IR-3 potently inhibited AIB uptake at low hormone concentrations, but this inhibition was overcome by high hormone concentrations, consistent with impairment of IGF-I action through the IGF-I receptor. In the case of insulin, the action of low concentrations (i.e. 10 ng/ml) was not inhibited, but that of higher insulin concentrations was, suggesting a dual receptor mechanism of cell stimulation by insulin. alpha IR-3 will be an important tool in further studies of the biology of the IGF-I receptor in normal and abnormal human cells.
一种针对人I型胰岛素样生长因子（IGF-I）受体（αIR-3）的单克隆抗体被用于区分胰岛素和IGF-I通过胰岛素介导的作用，而非通过人皮肤成纤维细胞上的IGF-I受体介导的作用。胰岛素和IGF-I均可刺激这些细胞摄取非代谢性丙氨酸类似物α-氨基异丁酸（AIB）。αIR-3以剂量依赖的方式抑制这两种激素刺激的AIB摄取。然而，在αIR-3存在的情况下，这两种激素的激素作用模式有所不同。对于IGF-I，αIR-3在低激素浓度下能有效抑制AIB摄取，但高激素浓度可克服这种抑制，这与通过IGF-I受体损害IGF-I作用一致。对于胰岛素，低浓度（即10 ng/ml）的作用未被抑制，但较高胰岛素浓度的作用被抑制，提示胰岛素对细胞刺激存在双受体机制。αIR-3将成为进一步研究正常和异常人类细胞中IGF-I受体生物学的重要工具。
