PMID- 19631248
OWN - NLM
STAT- MEDLINE
DCOM- 20100125
LR  - 20131121
IS  - 1872-9754 (Electronic)
IS  - 0197-0186 (Linking)
VI  - 55
IP  - 8
DP  - 2009 Dec
TI  - Synaptopathy under conditions of altered gravity: changes in synaptic vesicle 
      fusion and glutamate release.
PG  - 724-31
LID - 10.1016/j.neuint.2009.07.003 [doi]
AB  - Glutamate release and synaptic vesicle heterotypic/homotypic fusion were 
      characterized in brain synaptosomes of rats exposed to hypergravity (10 G, 1h). 
      Stimulated vesicular exocytosis determined as KCl-evoked fluorescence spike of 
      pH-sensitive dye acridine orange (AO) was decreased twice in synaptosomes under 
      hypergravity conditions as compared to control. Sets of measurements demonstrated 
      reduced ability of synaptic vesicles to accumulate AO ( approximately 10% higher 
      steady-state baseline level of AO fluorescence). Experiments with preloaded 
      l-[(14)C]glutamate exhibited similar amount of total glutamate accumulated by 
      synaptosomes, equal concentration of ambient glutamate, but the enlarged level of 
      cytoplasmic glutamate measuring as leakage from digitonin-permeabilized 
      synaptosomes in hypergravity. Thus, it may be suggested that +G-induced changes 
      in stimulated vesicular exocytosis were a result of the redistribution of 
      intracellular pool of glutamate, i.e. a decrease in glutamate content of synaptic 
      vesicles and an enrichment of the cytoplasmic glutamate level. To investigate the 
      effect of hypergravity on the last step of exocytosis, i.e. membrane fusion, a 
      cell-free system consisted of synaptic vesicles, plasma membrane vesicles, 
      cytosolic proteins isolated from rat brain synaptosomes was used. It was found 
      that hypergravity reduced the fusion competence of synaptic vesicles and plasma 
      membrane vesicles, whereas synaptosomal cytosolic proteins became more active to 
      promote membrane fusion. The total rate of homo- and heterotypic fusion reaction 
      initiated by Ca(2+) or Mg(2+)/ATP remained unchanged under hypergravity 
      conditions. Thus, hypergravity could induce synaptopathy that was associated with 
      incomplete filling of synaptic vesicles with the neuromediator and changes in 
      exocytotic release.
FAU - Krisanova, N V
AU  - Krisanova NV
AD  - The Dep. of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 
      Leontovicha St., Kiev 01601, Ukraine.
FAU - Trikash, I O
AU  - Trikash IO
FAU - Borisova, T A
AU  - Borisova TA
LA  - eng
PT  - Journal Article
DEP - 20090722
PL  - England
TA  - Neurochem Int
JT  - Neurochemistry international
JID - 8006959
RN  - 0 (Fluorescent Dyes)
RN  - 3KX376GY7L (Glutamic Acid)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - F30N4O6XVV (Acridine Orange)
RN  - I38ZP9992A (Magnesium)
SB  - IM
MH  - Acridine Orange/pharmacokinetics
MH  - Adenosine Triphosphate/metabolism
MH  - Animals
MH  - Brain/*metabolism/pathology/physiopathology
MH  - Calcium Signaling/physiology
MH  - Cell Compartmentation/physiology
MH  - Cognition Disorders/etiology/metabolism/physiopathology
MH  - Cytoplasm/metabolism
MH  - Disease Models, Animal
MH  - Exocytosis/physiology
MH  - Fluorescent Dyes/pharmacokinetics
MH  - Glutamic Acid/*metabolism
MH  - Hypergravity/*adverse effects
MH  - Magnesium/metabolism
MH  - Male
MH  - Membrane Fusion/physiology
MH  - Presynaptic Terminals/*metabolism/pathology
MH  - Rats
MH  - Rats, Wistar
MH  - Synaptic Transmission/*physiology
MH  - Synaptic Vesicles/*metabolism/pathology
MH  - Synaptosomes
EDAT- 2009/07/28 09:00
MHDA- 2010/01/26 06:00
CRDT- 2009/07/28 09:00
PHST- 2009/07/10 00:00 [received]
PHST- 2009/07/14 00:00 [accepted]
PHST- 2009/07/28 09:00 [entrez]
PHST- 2009/07/28 09:00 [pubmed]
PHST- 2010/01/26 06:00 [medline]
AID - S0197-0186(09)00227-7 [pii]
AID - 10.1016/j.neuint.2009.07.003 [doi]
PST - ppublish
SO  - Neurochem Int. 2009 Dec;55(8):724-31. doi: 10.1016/j.neuint.2009.07.003. Epub 
      2009 Jul 22.