Direct measurement of insulin is critical for basic and clinical studies of insulin secretion. However, current methods are expensive and time-consuming. We developed an insulin assay based on homogenous time-resolved fluorescence that is significantly more rapid and cost-effective than current commonly used approaches. This assay was applied effectively to an insulin secreting cell line, INS-1E cells, as well as pancreatic islets, allowing us to validate the assay by elucidating mechanisms by which dopamine regulates insulin release. We found that dopamine functioned as a significant negative modulator of glucosestimulated insulin secretion. Further, we showed that bromocriptine, a known dopamine D2/ D3 receptor agonist and newly approved drug used for treatment of type II diabetes mellitus, also decreased glucose-stimulated insulin secretion in islets to levels comparable to those caused by dopamine treatment.
Farino, Z. J., Morgenstern, T. J., Vallaghe, J., Gregor, N., Donthamsetti, P., Harris, P. E., … Freyberg, Z. (2016). Development of a rapid insulin assay by homogenous time-resolved fluorescence. PLoS ONE, 11(2). https://doi.org/10.1371/journal.pone.0148684