title: [Y-27632 induces calcium-independent glutamate release in rat brain synaptosomes by the mechanism which is distinct from exocytosis].
abstract: The inhibitor of Rho-kinase Y-27632 induces non-secretory exocytosis in PC12 cells. The influence of this compound on central synapses remains uninvestigated. We showed that Y-27632 at the concentration 100 jtM led to spontaneous [14C]glutamate release in synaptosomes, which was not accompanied by plasma membrane depolarization. Membrane potential was registered by fluorescent dye DiSC3(5). Y27632 induced an increase of acridine orange fluorescence, exercising no influence over fluorescence of FM2-10 dye. These results suggest that Rho-kinase inhibition decreases pH gradient of synaptic vesicles not inducing exocytosis. Dissipation of the gradient leads to leakage of neurotransmitters to cytosol pumping them out by plasma membrane transporters. Our results show the involvement of Rho-dependent branch of intracellular signaling in regulation of pH gradient in synaptic vesicles.
authors.forename: V V
authors.initials: VV
authors.lastname: Lemeshchenko
authors.forename: T G
authors.initials: TG
authors.lastname: Pekun
authors.forename: T V
authors.initials: TV
authors.lastname: Vasim
authors.forename: S V
authors.initials: SV
authors.lastname: Fedorovich
mesh_terms: D000577:Amides / Q000494:pharmacology*; D000818:Animals; D052160:Benzothiazoles / Q000378:metabolism; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002232:Carbocyanines / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D005456:Fluorescent Dyes / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008564:Membrane Potentials / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000378:metabolism; D016716:PC12 Cells; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D011726:Pyridinium Compounds / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D051381:Rats; D009435:Synaptic Transmission / Q000187:drug effects; D013572:Synaptic Vesicles / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D000577:Amides; D052160:Benzothiazoles; D002232:Carbocyanines; C086686:FM2 10; D005456:Fluorescent Dyes; D018377:Neurotransmitter Agents; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; C108830:Y 27632; D018698:Glutamic Acid; C012944:3,3'-dipropyl-2,2'-thiadicarbocyanine; D054460:rho-Associated Kinases; D002118:Calcium