Synergism of the pharmacological effect of glycine and thiotriazoline

Aim. To establish the effect of the glycine and thiotriazoline (4:1) combination on the parameters of the energy production of the mitochondria of the rat brain under the conditions of simulating an acute cerebrovascular accident. Materials and methods. The experimental part was performed on 90 male Wistar rats weighing 180–200 g. To model acute cerebrovascular accident (ACVA) by ischemic type, a classical model was used, where common carotid arteries had been ligated bilaterally. All animals were divided into 5 experimental groups: the first – intact (sham-operated rats, which during anesthesia had their common carotid arteries separated without ligation); the second – rats with ACVA (control); the third – rats with ACVA, which underwent intragastric administration of glycine at a dose of 200 mg/kg in the form of a tablet mass every day for 4 days; the fourth – rats with stroke, which every day for 4 days underwent intragastric administration of a combination of glycine and thiotriazoline (4:1) in the form of a tablet mass; the fifth – rats with ACVA, which underwent every day intragastric administration of piracetam in the form of a tablet mass at a dose of 500 mg/kg. The sampling of biological material (brain) for research was carried out on the fourth day of the experiment according to the standard method. The mitochondrial fraction was isolated by differential centrifugation in a refrigerated centrifuge. The manifestations of mitochondrial dysfunction, have been spectrophotometrically studied according to the degree of opening of the mitochondrial pore (MP) and mitochondrial transmembrane potential (Ψ). The assessment of the intensity of oxidative stress was determined by the markers of protein oxidative modification – aldehydephenylhydrazone (APH) and ketonedinitrophenylhydrazone (KPH) – spectrophotometrically. The state of energy metabolism was determined by the level of the most significant intermediates – ATP, lactate, succinate and malate. Results. In the group of animals with ACVA modeling, we noted a decrease in the level of ATP in mitochondria by 1.55 times, an increase in lactate content by 1.1 times, a decrease in SDH activity by 3.8 times and a decrease in succinate concentration by 1.1 times relative to the corresponding data of intact groups. Administration of a combination of glycine and thiotriazoline to experimental animals on the fourth day of ACVA modeling led to a 1.9-fold decrease in the opening of the mitochondrial pore and an increase in the charge of the inner mitochondrial membrane by 1.2 times, an increase in ATP in the mitochondrial fraction by 1.1 times, an increase in SDH activity by 3 times, and the activity of NAD-MDH – by 3.7 times, against the background of a decrease in the level of APH by 76.6 % and KPH by 80.7 %, relative to the group of animals with modeling of stroke by ischemic type. Conclusions. Modeling of ACVA leads to the initiation of oxidative stress and the development of an imbalance of energy metabolism intermediates in the brain mitochondria of experimental animals. Administration of a combination of glycine and thiotriazoline leads to a decrease in oxidative damage to mitochondria, increases the production of ATP due to the activation of compensatory mitochondrial-cytosolic shunts, mainly in malate-aspartate and succinate oxidase. In terms of the degree of influence on the indicators of energy metabolism, the combination of glycine and thiotriazoline reliably exceeds the similar actions of glycine and the reference drug - piracetam.

Correction of mitochondrial dysfunction by succinic acid derivatives under experimental cerebral ischemia conditions

The aim of the study. To evaluate the effect of succinic acid derivatives on changes of mitochondrial function in rats under cerebral ischemia conditions. Materials and methods. In this work, the effect of succinic acid, ethylmethylhydroxypyridine succinate, and acetylaminosuccinic acid at doses of 50 mg/kg, 100 mg/kg, and 200 mg/kg (per os) on the change of the neuronal mitochondria function was studied. Cerebral ischemia was reproduced by the Tamura method. The following parameters were evaluated: changes in aerobic/anaerobic metabolism, mitochondrial membrane potential, the opening rate of the mitochondrial pore of transitional permeability and the activity of apoptotic systems. Results. During the study, it was found that the use of the test-compounds at doses of 100 mg/kg and 200 mg/kg contributed to an increase in ATP-generating activity, as well as the maximum respiration level and respiratory capacity, while accompanied by a decrease in the intensity of anaerobic metabolism reactions. Also, upon administration of the test succinic acid derivatives, an increase in the mitochondrial membrane potential and latent opening time of the mitochondrial pore transitional permeability were observed. Moreover, the activity of caspase-3 and apoptosis-inducing factor on groups treated by test objects at doses of 100 mg/kg and 200 mg/kg was significantly lower than that in untreated animals. Conclusion. The studied succinic acid derivatives contribute to the restoration of mitochondrial function in cerebral ischemia conditions, while the most effective dose can be considered to be 100 mg/kg.

P0017ESTIMATION OF KIDNEY MITOCHONDRIA TOLERANCE VIA FLUORESCENCE MICROSCOPY

Background and Aims The functioning of mitochondria is a key parameter that determines the normal activity of kidney cells and triggers life/death transition in pathological conditions. The main pathological event in the mitochondria is the opening of a permeability transition pore, observed in renal ischemia and other acute nephrological pathologies. The development of non-specific mitochondrial permeability leads to a burst of ROS generation and the release of proapoptotic factors. Assessment of mitochondrial resistance to induction of permeability transition is an important characteristic for the analysis of kidney tolerance to damaging factors, such as ischemia. In this study, we developed a method for evaluating mitochondrial permeability transition in renal tubular cell culture using fluorescence microscopy. Method The primary renal tubular epithelial cells were loaded with a fluorescent probe, TMRE, which accumulates in the mitochondria depending on the transmembrane potential. Cells in the culture were analyzed on a fluorescent microscope for 180 seconds under constant exposure with exciting light and the video was recorded at a frequency of 1 frame/sec. To analyze the images, a Python algorithm was created that allocated the individual mitochondria in the image and analyzed the shape, size, and dynamics of the TMRE fluorescence of each mitochondrion. In total, more than 10^5 mitochondria were analyzed in each experiment. Results The initial state of mitochondrial transmembrane potential was evaluated by the intensity of TMRE fluorescence in the first frame in each series when phototoxicity of the dye was not manifested yet. Population analysis revealed that the total distribution of mitochondria by TMRE fluorescence intensity was a single-modal. In this case, the histogram of the distribution had a wide arm of mitochondria with greater TMRE fluorescence (that means high transmembrane potential). This distribution suggests that renal cells have mitochondria with high and low TMRE fluorescence values. This can be interpreted as the presence of mitochondria in cells with higher transmembrane potential values. Analysis of the dynamics of TMRE fluorescence intensity revealed that some mitochondria after a certain time demonstrated a sharp drop in the fluorescence intensity, which we interpret as the opening of the mitochondrial pore (Fig.1). However, this drop did not occur in all kidney cells mitochondria, but only in about 15% of the cells. A small number of mitochondria had several repeated falls/rises in TMRE fluorescence. This can be interpreted as the closing and subsequent opening of the permeability transition pores. Analysis of a subpopulation of mitochondria with low TMRE values revealed that low-energized mitochondria have a later pore opening time. It is important to note that mitochondria with higher TMRE fluorescence are more susceptible to photodynamic effects when the probe is excited by light. Conclusion Renal epithelial cells happen to be very heterogeneous in terms of mitochondrial potential and the time of the induction of mitochondrial permeability transition. Correlations were found between the value of the mitochondrial potential (TMRE accumulation) and the cell's resistance to induction of non-specific mitochondrial pore.

The influence of the supramolecular complex PRE -1 on permeability of membranes of mitochondria

The change in the state of the mitochondrial pore of nonspecific conductivity plays a key role in the processes of triggering and regulating apoptosis. Therefore, the study of mechanisms of opening and regulating the state of these pores can have a great importance to find the ways of correcting many mitochondrial dysfunctions, including those which are associated with age-related changes. In our work, we have done a comparative analysis for swelling of brain mitochondria of adult (9 months) and mature rats (12-15 months).