Insulin binding to microvascular endothelium of intact heart: a kinetic and morphometric analysis.
Insulin binding to microvascular endothelium of intact heart: a kinetic and morphometric analysis.
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胰岛素与完整心脏的微血管内皮结合：动力学和形态分析。
DOI：
10.1152/ajpendo.1983.244.5.e447
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Owen,WG
中科院分区：
文献类型：
--
作者：
Bar,RS;DeRose,A;Sandra,A;Peacock,ML;Owen,WG
我们研究了胰岛素与完整、跳动的心脏血管的结合。跳动中的心脏先灌流[125I]碘胰岛素(3×10(-10)M)，然后再灌流未标记的胰岛素。未标记的胰岛素取代结合的[125I]碘胰岛素，与未标记激素的浓度成正比。未标记胰岛素在10(-11)M时引起[~(125)I]碘胰岛素的显著移位，在10(-6)M时效应最大，并以剂量依赖方式移位[~(125)I]碘胰岛素，效力相当于胰岛素的1%。灌流无关多肽不起作用。~(125)I颗粒的放射自显影计数表明，95%以上的颗粒分布在微血管内。当在10(-6)M处灌流[125I]碘胰岛素后，微血管颗粒数减少了50%(与单独灌流[125I]碘胰岛素相比)；同时灌流[125I]碘胰岛素和10(-6)M未标记胰岛素，颗粒数减少了80%。电子显微镜放射自显影显示~(125)I颗粒与血管内皮细胞结合。我们的结论是，在完整的心脏中，微血管内皮细胞上存在特定的胰岛素受体。
We have studied insulin binding to blood vessels of the intact, beating heart. The beating hearts were perfused with [125I]iodoinsulin (3 X 10(-10) M) followed by perfusion with unlabeled insulin. The unlabeled insulin displaced the bound [125I]iodoinsulin in direct proportion to the concentration of the unlabeled hormone. Perfusion with unlabeled insulin at 10(-11) M elicited a significant displacement of [125I]iodoinsulin, with a maximal effect at 10(-6) M. Unlabeled proinsulin also displaced [125I]iodoinsulin in a dose-dependent manner, being 1% as potent as insulin. Perfusion with unrelated peptides had no effect. Radioautographic counting of 125I grains indicated that greater than 95% of the grain counts over blood vessels were within the microvessels. When [125I]iodoinsulin perfusion was followed by perfusion with unlabeled insulin at 10(-6) M, there was a 50% decrease in grain counts over the microvessels (versus perfusion with [125I]iodoinsulin alone); with coperfusion of [125I]iodoinsulin and 10(-6) M unlabeled insulin, an 80% decrease in grain counts occurred. Electron microscopic radioautography indicated that the 125I grains were associated with the vascular endothelial cells. We conclude that specific insulin receptors are present on endothelial cells of microvessels in the intact heart.