Influence of chronic alcoholic intoxication and lighting regime on karyometric and ploidometric parameters of hepatocytes of rats

The features of the diurnal dynamics of the area of rat hepatocyte nuclei and their ploidy were studied under conditions of a standart (fixed) light regime and constant illumination, as well as under chronic exposure to alcohol in the mentioned light regimes. It has been shown that exposure to alcohol and exposure to constant illumination separately lead to a change in the amplitude-phase characteristics of the circadian rhythm of the nucleus area, while the combined effect of these factors leads to a complete destruction of the rhythm, which indicates a violation of adaptation processes. An increase in the average ploidy of hepatocyte nuclei in chronic alcohol intoxication is also shown, while in animals kept under constant illumination without drinking alcohol, the values of this parameter decrease, which indicates a successful course of the adaptation process. The conducted research indicates that the results of karyometric and ploidometric analysis characterize the degree of influence of alcohol intoxication and changes in the light regime on the liver of rats, reflecting the rate of efficiency of adaptation to these factors.

Morphometric analysis of supraoptic neurons of the rat hypothalamic nuclei under conditions of prolonged illumination

The article reviews the results of studies of the morphofunctional state of neurons of the supraoptic nuclei of the rat hypothalamus under conditions of different duration of light regime. Under standard light regime in rats, a diurnal rhythm of morphofunctional activity of supraoptic nucleus neurons with maximum activity during daytime (before 2 p.m.) is recorded. In animals subjected to prolonged light exposure, more pronounced changes in the morphofunctional state of the supraoptic neurons of the hypothalamus at 2 a.m. than at 2 p.m. were established. Thus, the neuronal nucleus area was 94.08 ± 9.55 μm2 and was significantly greater than that in intact animals. The nucleo-cytoplasmic ratio of supraoptic hypothalamic neuron at 2 a.m. was lower than that in intact animals due to a decrease in specific nucleus volume. In comparison with the day period (2 p.m.), before 2 a.m. there was revealed a decrease of the neuron body area of supraoptic nuclei of hypothalamus due to possible decrease of the area of nucleus and nucleolus of cells. This was the reason for the increase in the nucleo-cytoplasmic ratio in the neurons under observation at night, which was 2.51 ± 0.023 units. Constant light regime did not cause inversion of the rhythm of morphofunctional activity of the neurons under study, the maximum values, as in intact animals, occurred in the daytime observation period.

The effect of a complex of melatonin, aluminum oxide and polymethylsiloxane on the cellular composition of the mice spleen kept in round-the-clock lighting conditions

It is known that the circadian rhythm of melatonin production depends on the intensity of illumination. Violation of the light regime leads to suppression of melatonin synthesis and the development of desynchronosis, which increases the risk of developing a number of pathologies. In this regard, it is relevant to search for opportunities to restore disturbed circadian rhythms and, especially, to correct immune dysfunctions that occur in these situations.The aim of this study was to examine the effect of a complex of melatonin, aluminum oxide and polymethylsiloxane on the lymphocytes of the spleen of mice kept under round-the-clock lighting.Materials and methods. Mice of the C57Bl/6J line were kept under round-the-clock lighting for 14 days, against which they were intragastrically injected with distilled water, aluminum oxide with polydimethylsiloxane, melatonin and a complex of melatonin, aluminum oxide and polymethylsiloxane (a new drug developed by the Research Institute of Clinical and Experimental Lymphology – Branch of the Federal Research Center Institute of Cytology and Genetics SB RAS; Patent of Russian Federation No. 2577580, 2016), represented by a complex of porous material (aluminum oxide with polydimethylsiloxane) and melatonin, immobilized in the pores, from which it is gradually released in a liquid medium. Intact animals kept under the light regime of ST 12/12 and under round-the-clock lighting served as a control. Immunophenotyping of spleen B- and T-lymphocytes was performed on a flow cytofluorimeter with monoclonal antibodies APC CD3 and FITC CD19. For studying the distribution of cells by stages of the cell cycle in splenocytes, the amount of intracellular DNA was measured by the level of inclusion of propidium iodide.Results. Flow cytometry of the distribution of B- and T-lymphocytes of the spleen in male mice of the C57Bl/6J line kept under round-the-clock lighting conditions (KO 24/0 h) revealed a decrease in the percentage of B-lymphocytes and an increase in the number of T-lymphocytes, compared with animals kept under standard lighting conditions (the light/dark photoperiod – 14/10 hours). The ratio of CD19+/CD3+ lymphocytes of the spleen in mice under the conditions of KO significantly decreases (1.5 times) compared to intact animals (p ≤ 0.001). The administration of pure and modified melatonin (Complex M) to animals kept under round-the-clock lighting conditions has an equally pronounced normalizing effect on the cellular composition of B- (CD19) and T- (CD3) lymphocytes of the spleen, bringing the values of the studied parameters to the control values of the intact animals (p ≤ 0.001) Round-the-clock lighting affects the proliferative potential of splenocytes, reducing the number of cells in the G2/M phase, compared with animals treated with melatonin (p ≤ 0.050). The introduction of melatonin leads to an increase in the percentage of cells in the G2/M phase relative to the placebo group (p ≤ 0.050). In the group of mice treated with Complex M, the greatest increase in cells at the S + G2/M phases and the highest percentage of cells at the G2/M phase were revealed compared to the placebo control group (p ≤ 0.050).Conclusion. The complex of melatonin, aluminum oxide and polymethylsiloxane has additional immunotropic properties in relation to the modifier molecule, which, apparently, are due to the joint immunostimulating effect of melatonin and the lymphostimulating effect of the sorbent. Melatonin in the composition of the complex shows its properties more stably.

Phytoindication assessment of the effect of reconstruction on the light regime of an urban park

The ecological restoration of urban parks is used to increase their recreational attractiveness, improve air quality, mitigate urban heat island effects, improve stormwater infiltration, and provide other social and environmental benefits. The dynamics of plant communities after urban forest restoration requires investigation. The study assessed the impact of urban park reconstruction on the state of grass cover, phytoindication of changes in light regime caused by park reconstruction and found out the dependence of reliability of phytoindication assessment on the number of species in the relevant area. The study was conducted in the recreational area of the Botanical Garden of the Oles Honchar Dnipro National University (Ukraine). A tree plantation was created after the Second World War in the location of a natural oak forest. In 2019, a 2.8 ha area of the park was reconstructed. The samples were taken within polygons, two of which were placed in the reconstruction area and two of which were placed in a similar section of the park where no reconstruction was performed. During the reconstruction process, walkways were rebuilt, shrubs were removed, old, damaged trees were removed, and tree crowns were trimmed. Juvenile trees were planted in place of the removed old trees. Old outbuildings, which greatly impaired the aesthetic perception of the park, were also removed. Transport and construction machinery was involved in the reconstruction. A total of 65 plant species were found within the studied polygons. The number of herbaceous species in the park area after reconstruction was higher than without reconstruction. The crown closure in the reconstructed area was significantly lower than that in the untreated conditions. The phytoindication assessment showed that the light regime varies from the conditions suitable for the scyophytes (plants of typical foliage forests) to the conditions suitable for the sub-heliophytes (plants of light forests and shrubberies, or high herbaceous communities; lower layers are in the shade). The light regime in the park area after reconstruction was statistically significantly different from the regime in the untreated park area. The lighting regime after the reconstruction was favourable to sub-heliophytes, and without reconstruction the regime favoured hemi-scyophytes. Tree canopy crown closure negatively correlated with grass height and herbaceous layer projective cover. The tree canopy crown closure, grass height, and herbaceous layer projective cover were able to explain 86% of the phytoindication assessment of the lighting regime variation. These parameters negatively affected the light regime. The prospect of further research is to investigate the dependence of indicative reliability of the assessment of other environmental factors with the help of phytoindication depending on the number of species. In addition to the indication of traditional ecological factors it is of particular interest to clarify the aspect of the dynamics of hemeroby indicators as a result of park reconstruction.

Ecological characteristics of the flora of the Basegi mountains (Perm krai)

В статье оценивается флора хребта Басеги по ряду экологических факторов: водному, световому режимам, богатству почв элементами минерального питания. По водному режиму наблюдается преобладание мезофитов - 53,4%. По световому режиму приблизительно равное соотношение светолюбивых (50,1%) и теневыносливых (47,5%) видов. По богатству почв элементами минерального питания явно преобладают мезотрофы - 72,5%. Территорию можно охарактеризовать, как с преобладанием умеренно увлажненных местообитаний, равным соотношением сообществ без выраженного затенения и выраженным затенением нижних ярусов, и умеренным содержанием в почвах элементов минерального питания. Аналогичная ситуация прослеживается и по высотным поясам, кроме горно-лесного пояса, где по световому режиму преобладают теневыносливые виды. The article assesses the flora of the Basegi Ridge by a number of environmental factors: water, light conditions, and the richness of soil elements with mineral nutrition. The water regime is dominated by mesophytes - 53,4%. According to the light regime, the ratio of light-loving (50,1%) and shade-tolerant (47,5%) species is approximately equal. Soils rich with mineral elements are clearly dominated by mesotrophs - 72,5%. The territory can be characterized as having a predominance of moderately moist habitats, an equal ratio of communities without pronounced shading and pronounced shading of the lower tiers, and a moderate content of mineral nutrition elements in the soils. A similar situation is observed in high-rise belt, except for the mountain-forest belt, where shade-tolerant species predominate in the light regime

EFFECT OF CHRONIC ALCOHOLINTOXICATION AND CONSTANTLIGHTING ON CARDIOVASCULAR PARAMETERS IN MALE R

The aim of the research was to study the effect of chronic alcohol intoxication and constant il-lumination on the circadian rhythms (CR) of some parameters of the cardiovascular system in rats separately, as well as to study the rhythms of these parameters under the combined action of chronic alcohol intoxication (CAI) and constant illumination. It was found that chronic alcohol intoxication CAI at a fixed light regime causes a decrease in heart rate, an increase in SBP and PP; no changes were noted at CAI under constant lighting. At the same time, constant illumina-tion without ethanol exposure results in a decrease in heart rate and an increase in PP. At the same time, CAI with a fixed light regime leads to the destruction of CR of all parameters, except for MBP; at constant illumination with CAI no circadian rhythms of HR, DBP, PP and MBP are detected. Constant illumination leads to the destruction of the CR of PP. Among the remaining CRs, the heart rate rhythm, which is extant in the second group, persists practically unchanged, but the characteristics of all other CRs change significantly in comparison with control.