FM1-43 measurements of local exocytotic events in rat melanotrophs.
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.
Sikdar
S K
SK
Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Medical Faculty, University of Ljubljana Medical School, Zaloska 4, SI-1000 Ljubljana, Slovenia.
Kreft
M
M
Pangrsic
T
T
Grilc
S
S
Zorec
R
R
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
C073804:FM1 43; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D018698:Glutamic Acid