Bar R S, Boes M, Clemmons D R, Busby W H, Sandra A, Dake B L, Booth B A
V.A. Hospital, Department of Medicine, Iowa City, Iowa.
Endocrinology. 1990 Jul;127(1):497-9. doi: 10.1210/endo-127-1-497.
Insulin-like growth factor binding-proteins 1 and 2 (IGFBP-1, IGFBP-2) and endothelial cell IGF binding proteins (ECBP) were individually perfused through isolated beating rat hearts in the absence and presence of insulin. Insulin caused an increased movement of IGFBP-1 from the vascular space to tissues of the heart. Subendothelial content of IGFBP-1 was 110%, 126% (p less than .01) and 132% (p less than 0.05) of control hearts when perfused with 1, 10 and 100 ng/ml insulin, respectively. . In contrast, insulin treatment was associated with a decrease in ECBP content in cardiac tissue, being 83%, 62% (p less than 0.005) and 73% (p less than 0.05) of control when perfused with 1, 10 and 100 ng/ml insulin. The efflux of IGFBP-2 from the intravascular space was unaffected by insulin. The subendothelial tissue distribution of the transported binding proteins was not changed by insulin perfusion, with IGFBP-1 and IGFBP-2 localizing predominantly in cardiac muscle and ECBP having greater affinity for connective tissue elements. We conclude that in the perfused rat heart, insulin can differentially alter transcapillary movement of IGFBP-1, IGFBP-2 and endothelial cell IGF-binding proteins. Such insulin-facilitated changes could potentially mediate nutrient-dependent transport of IGF-I and IGF-II to peripheral tissues.
胰岛素样生长因子结合蛋白1和2（IGFBP - 1、IGFBP - 2）以及内皮细胞IGF结合蛋白（ECBP）分别在有无胰岛素的情况下灌注到离体跳动的大鼠心脏中。胰岛素导致IGFBP - 1从血管腔向心脏组织的转运增加。当分别用1、10和100 ng/ml胰岛素灌注时，心脏内膜下IGFBP - 1的含量分别是对照心脏的110%、126%（p < 0.01）和132%（p < 0.05）。相反，胰岛素处理与心脏组织中ECBP含量的降低有关，当用1、10和100 ng/ml胰岛素灌注时，其含量分别是对照的83%、62%（p < 0.005）和73%（p < 0.05）。IGFBP - 2从血管内空间的流出不受胰岛素影响。胰岛素灌注并未改变转运的结合蛋白在内膜下组织的分布，IGFBP - 1和IGFBP - 2主要定位于心肌，而ECBP对结缔组织成分具有更高的亲和力。我们得出结论，在灌注的大鼠心脏中，胰岛素可差异性地改变IGFBP - 1、IGFBP - 2和内皮细胞IGF结合蛋白的跨毛细血管转运。这种胰岛素促进的变化可能潜在地介导IGF - I和IGF - II依赖营养物质向周围组织的转运。
