Binding, internalization, and degradation of [125I]insulin by cultured bovine aortic endothelial cells: effects of serotonin.
Cultured bovine aortic endothelial cells bind and internalize [125I]insulin and down regulate insulin receptors. Internalized insulin was not degraded significantly and diffused from the endothelial cells. Neither 5-hydroxytryptamine, methylamine, nor dansylcadaverine have any observable effect on insulin binding, internalization, metabolism, or down regulation of insulin receptors. Transglutaminase activity, however, is inhibited by 5-hydroxytryptamine and methylamine. These data indicate that transglutaminase is not required for insulin receptor-mediated endocytosis by bovine aortic endothelial cells in culture.
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D007457:Iodine Radioisotopes; D011485:Protein Binding / Q000187:drug effects; D011972:Receptor, Insulin / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*
D007328:Insulin; D007457:Iodine Radioisotopes; D012701:Serotonin; D011972:Receptor, Insulin