We adapted a radioligand receptor binding assay for measuring insulin levels in unknown samples. The assay enables rapid and accurate determination of insulin concentrations in experimental samples, such as from insulin-secreting cells. The principle of the method is based on the binding competition of insulin in a measured sample with a radiolabeled insulin for insulin receptor (IR) in IM-9 cells. Both key components, radiolabeled insulin and IM-9 cells, are commercially available. The IR binding assay was used to determine unknown amounts of insulin secreted by MIN6 β cell line after stimulation with glucose, arginine, ornithine, dopamine, and serotonin. The experimental data obtained by the IR binding assay were compared to the results determined by RIA kits and both methods showed a very good agreement of results. We observed the stimulation of glucose-induced insulin secretion from MIN6 cells by arginine, weaker stimulation by ornithine, but inhibitory effects of dopamine. Serotonin effects were either stimulatory or inhibitory, depending on the concentration of serotonin used. The results will require further investigation. The study also clearly revealed advantages of the IR binding assay that allows the measuring of a higher throughput of measured samples, with a broader range of concentrations than in the case of RIA kits. The IR binding assay can provide an alternative to standard RIA and ELISA assays for the determination of insulin levels in experimental samples and can be especially useful in scientific laboratories studying insulin production and secretion by β cells and searching for new modulators of insulin secretion.

• Klíčová slova
• Binding assay, Insulin receptor, Insulin secretion, Radioligand, Secretagogue, β Cells,
• MeSH
• arginin metabolismus   MeSH
• beta-buňky metabolismus   MeSH
• buněčné linie MeSH
• dopamin metabolismus   MeSH
• glukosa metabolismus   MeSH
• inzulin analýza   metabolismus   MeSH
• krysa rodu Rattus MeSH
• Langerhansovy ostrůvky metabolismus   MeSH
• lidé MeSH
• myši MeSH
• ornithin metabolismus   MeSH
• potkani Wistar MeSH
• radioimunoanalýza metody   MeSH
• radioligandová zkouška metody   MeSH
• sekrece inzulinu * MeSH
• serotonin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arginin MeSH
• dopamin MeSH
• glukosa MeSH
• inzulin MeSH
• ornithin MeSH
• serotonin MeSH