Schmid C, Schläpfer I, Keller A, Waldvogel M, Froesch E R, Zapf J
Dept. of Medicine, University Hospital, Zürich, Switzerland.
Biochem Biophys Res Commun. 1995 Jul 6;212(1):242-8. doi: 10.1006/bbrc.1995.1962.
IGFBP-3 and IGFBP-6 were used to study whether both IGF I and IGF II play a role in auto-/paracrine stimulation of rat osteoblast growth. Both IGFBPs decreased basal DNA synthesis in neonatal rat calvaria cells but with different potencies. Consistent with their IGF binding affinities, IGFBP-3 blocked both IGF I- and IGF II-stimulated DNA synthesis, whereas IGFBP-6 preferentially blocked IGF II-stimulated DNA synthesis. These inhibitory effects of the two IGFBPs can be fully explained by the sequestration of IGFs. Because IGFBP-6 preferentially binds IGF II and is much less potent than IGFBP-3 in decreasing basal DNA synthesis in calvaria cells, IGF I but not IGF II appears to be an important auto-/paracrine stimulator of DNA synthesis.
使用胰岛素样生长因子结合蛋白-3（IGFBP-3）和胰岛素样生长因子结合蛋白-6（IGFBP-6）来研究胰岛素样生长因子I（IGF I）和胰岛素样生长因子II（IGF II）是否在大鼠成骨细胞生长的自分泌/旁分泌刺激中发挥作用。两种IGFBP均降低新生大鼠颅骨细胞的基础DNA合成，但效力不同。与它们对IGF的结合亲和力一致，IGFBP-3阻断IGF I和IGF II刺激的DNA合成，而IGFBP-6优先阻断IGF II刺激的DNA合成。这两种IGFBP的这些抑制作用可以通过IGF的隔离来充分解释。由于IGFBP-6优先结合IGF II，并且在降低颅骨细胞基础DNA合成方面的效力远低于IGFBP-3，因此IGF I而非IGF II似乎是DNA合成的重要自分泌/旁分泌刺激因子。
