Role of calcium in exocytosis induced by hypotonic swelling.
We studied the influence of Ca(2+) on exocytosis induced by hypotonic shock using the fluorescent dyes acridine orange FM1-43 and FM2-10. It was shown using acridine orange that lowering osmolarity to 230 mOsm/L induces exocytosis both in calcium-containing and calcium-free media. By contrast, we were able to demonstrate calcium dependence of exocytosis using styryl dyes. Lowering osmolarity leads to an increase of neurotransmitter release in a calcium-independent manner. Thus, our data suggest that hypotonic swelling induces calcium-independent exocytosis. Calcium influx mediated by stretch channels is able to switch mode of exocytosis from "kiss and run" to full fusion.
Fedorovich
Sergei V
SV
Institute of Biophysics and Cell Engineering, Minsk, Belarus. lbpm@biobel.bas-net.by
Waseem
Tatyana V
TV
Lavrukevich
Tatyana V
TV
Konev
Sergei V
SV
D000165:Acridine Orange / Q000737:chemistry; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D005089:Exocytosis / Q000187:drug effects* / Q000502:physiology; D005456:Fluorescent Dyes / Q000737:chemistry*; D007038:Hypotonic Solutions; D009474:Neurons / Q000502:physiology*; D009994:Osmolar Concentration; D011726:Pyridinium Compounds / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects* / Q000502:physiology
C086686:FM2 10; D005456:Fluorescent Dyes; D007038:Hypotonic Solutions; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D000165:Acridine Orange; D002118:Calcium