Нитрозирующий стресс и апоптоз нейронов СА1-зоны гиппокампа в условиях моделирования хронической алкогольной интоксикации: нейропротективные эффекты тиоцетама

Abstract

Abstract. Fulfilled researches showed that modeling of chronic alcohol intoxication by daily intragastric ethanol administration to non‐pedigreed male white rats (first 10 days – 15% ethanol solution in dose 4 g/kg, next 10 days – 15% ethanol solution in dose 6 g/kg, then 10 days – 25% ethanol solution in dose 4 g/kg) leads to activation of nitrosorbidi stress reactions and initiation of neuro‐apoptosis. Thus, as compared with healthy animals group, in rats’ brain after chronic ethanol administration it was revealed significant increase of nitro‐tyrosine (nitrosorbidi stress marker) in cytosolic and mitochondrial fractions of brain homogenate against the background of revealing of apoptosis molecular markers in hippocampal CA1 zone neurons (fragmentation of neuronʹs nuclei of hippocampal CA1 zone, increase of density and ratio of apoptotic‐ and destructive‐changed cells) as well as deprivation of anti‐apoptotic mechanisms (decrease of density of Bcl‐2‐positive neurons in hippocampal CA1 zone and decrease of Bcl‐2 protein concentration in hippocampus). Subsequent 14‐day intragastric administration of complex neuro‐metabolic cerebro‐protector Thiocetam in dose 100 mg/kg to the animals after chronic alcoholization showed significant protective effect on hippocampal CA1 zone neurons. Thus, Thiocetam administration resulted in decrease of nitrotyrosine levels in mitochondrion and in cytosol of brain of animals with chronic alcoholization as compared with untreated animals and with animals receiving Piracetam. Thiocetam administration to experimental animals led to significant decrease of density of apoptotic‐ and destructive‐changed neurons of hippocampal CA1 zone and ratio of apoptotic‐changed cells as compared with control group and animals receiving Piracetam. Course of treatment with Thiocetam increases significantly the density of Bcl‐2‐ positive neurons in CA1 zone of hippocampus and significantly increases concentration of Bcl‐2 in brain tissue of experimental animals as compared with control group and animals which received Piracetam according the same schedule. The increase of Bcl‐2 protein expression in animals received Thiocetam testifies to the activation of anti‐apoptotic defense of damaged neurons under the influence of this preparation. We suppose that one of the molecular mechanisms of neuro‐protective effect of Thiocetam in chronic intoxication is the breaking of NO‐depended mechanisms of neuro‐apoptosis.