We have explored the existence of fusion- and secretion-competent sites on the plasma membrane of peptide secreting rat pituitary melanotrophs at rest, and following stimulation with glutamate. We monitored changes in fluorescence of FM1-43, a styryl dye which labels plasma membrane. The results show spontaneous local increases in FM1-43 reporting changes in membrane surface area due to cumulative exocytosis. Addition of glutamate, further increased the occurrence of these events. Statistical analysis of local FM1-43 fluorescence changes suggests that this is due to the recruitment of inactive exocytotic domains and due to the stimulation of already active exocytotic domains. © 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Sikdar, S. K., Kreft, M., Pangrsic, T., Grilc, S., & Zorec, R. (2005). FM1-43 measurements of local exocytotic events in rat melanotrophs. FEBS Letters, 579(29), 6575–6580. https://doi.org/10.1016/j.febslet.2005.10.049