Tamara I. Lyskova

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Brain ischemia is accompanied by lowering of intra- and extracellular pH. Stroke often leads to irreversible damage of synaptic transmission by unknown mechanism. We investigated an influence of lowering of pHi and pHo on free radical formation in synaptosomes. Three models of acidosis were used: (1) pHo 6.0 corresponding to pHi decrease down to 6.04; (2)(More)
The influence of acidosis on the transmembrane potential, sodium pump and membranous systems of calcium transport was studied on isolated presynaptic nerve terminals (synaptosomes) from rat brain. It is established that acidic shift causes a decrease of membrane potential, a large inhibition of the sodium pump (by three times at pH 6.0). All the systems(More)
Below 37 degrees the mobility of lipids in rat brain synaptic membranes evaluated by the spin probe method is higher in old (24-26 months) than in young (5-6 months) animals. The number of ouabain receptors in membranes increases with age, while maximum rate and Km values are not changed. The relation between structural state of membrane and properties of(More)
Accumulation of TBA-reactive substances after a 40 min incubation of rat brain synaptosomes at 37 degrees C was analysed. A lowering of pH to 6.5-5.5 or arachidonic acid (0.1-1.0 mM) increased lipid peroxidation which was blocked by antioxidants. Acidosis (pH 6.0) and arachidonic acid used in combination had a strong synergic effect. Depolarisation of(More)
In contrast to the purified enzyme. Na, K-ATPase from intact synaptic membranes is inhibited by Ca2+ according to a biphase pattern at Ca2+ concentrations of 10(-6) to 10(-3) M. The membrane damage after three washings with bidistilled water results in elimination of low cocentration phase. Recombination of the sediment and the supernatant restores the(More)
The effect of protein cross-linkage on proton translocation and electron transport in mitochondria respiratory chain was studied. Dimethylsuberimidate (1 mM) or dicyclohexyl carbodiimide (50 g/ml) inhibit proton translocation with concomitant stimulation of respiration. It is concluded that the definite level of dynamic mobility of proteins is needed for(More)
Norepinephrine stimulates Na, K-ATPase from rat brain homogenates at concentrations of 10(-4)--10(-5) and 10(-7)--10(-8) M. A low concentration maximum is observed after 48 hrs of incubation at -20 degrees C and is not changed by the addition of alpha-tocopherol, glycerol and MAO inhibitor ipraside. The maximum observed at the mediator concentration equal(More)