title: FM1-43 measurements of local exocytotic events in rat melanotrophs.
abstract: 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.
authors.affiliation: Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Medical Faculty, University of Ljubljana Medical School, Zaloska 4, SI-1000 Ljubljana, Slovenia.
authors.forename: S K
authors.initials: SK
authors.lastname: Sikdar
authors.forename: M
authors.initials: M
authors.lastname: Kreft
authors.forename: T
authors.initials: T
authors.lastname: Pangrsic
authors.forename: S
authors.initials: S
authors.lastname: Grilc
authors.forename: R
authors.initials: R
authors.lastname: Zorec
mesh_terms: D000818:Animals; D002462:Cell Membrane; D005089:Exocytosis / Q000187:drug effects; D005456:Fluorescent Dyes; D018698:Glutamic Acid / Q000494:pharmacology; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism*; D008722:Methods; D010902:Pituitary Gland / Q000166:cytology*; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D051381:Rats; D017208:Rats, Wistar
chemical_list: C073804:FM1 43; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D018698:Glutamic Acid