Exposure of Parental Rats to Mercury Chloride during Progenesis Affects the CNS Parameters of the Adult Offspring

No more than 100 nm large, nanoparticles (NPs) are distinguished by unusual mechanical, electrical, optical, thermal and magnetic properties. They are used in biology, pharmacology, medicine, chemistry, physics, materials technology and engineering industry. Nanoparticles penetrate in organism through the skin, GIT and airways. Their genotoxicity depends on size, form, mode of action and composition. Two principal mechanisms of NPs genotoxicity are primary and secondary. The primary mechanism is realized in direct interaction with the genome; the secondary mechanism is achieved through mediation of the active forms of oxygen. NPs can modulate the epigenome by altering the gene functions and do not change the DNA sequence directly. Consequences of prolonged exposure to low NPs doses on the human organism still remain uninvestigated.

The assessment of the indicators of the reproductive potential of male white rats exposed to smoke for 1 month was carried out. Examination of exposed animals included determination of the spermatogenesis index and the level of DNA fragmentation and methylation in the testes and blood. A statistically signifi-cant increase in the level of genome-wide methylation in the blood of rats exposed to smoke was revealed. A morphometric study of the testis tissue revealed a violation of spermatogenesis indices in exposed rats.

An analysis of the acute and subacute toxicity of a copper oxide nanocomposite (NC) encapsulated in natural polymeric matrix of arabinogalactan is presented. The study was carried out in two stages. At the first stage, the acute toxicity of the NC was studied. For this, white mice were orally administered one time with an aqueous solution of NC at a dose 2000 mg/kg. The study demonstrated that according to this parameter, NC belongs to low-toxicity substances of hazard class 5. At the second stage, the biological response of the white rats was evaluated with a subacute intragastric effect of Cu2ОAG NC at a dose of 500 µg/kg (based on Cu) body weight within 10 days. The study demonstrated an increase in the contents of copper in the brain tissue, liver, and kidneys compared with the control group. Morphological and neurophysiological changes were detected in white rats treated with this NC. A pronounced macrophage reaction consisting in an increase in the number of Kupffer cells in the organ sinusoids was observed in liver tissue. In the tissues of the sensorimotor cortex of the brain, a sharp decrease in the number of astroglia cells was detected, which indicates a selective cytotoxicity of this NC. When studying the bioelectric activity of the sensorimotor cortex of the brain in animals a decrease in β-2 rhythm of background electroencephalogram, as well as a decrease in the amplitude of the P2 and N2-P3 peaks of the visually evoked potentials, were observed. No genotoxic effects were detected under the influence of the NC.

The use of a developed experimental model of a natural fire made it possible to assess the consequences of 24 h exposure to peat combustion products in albino rats. Peat smoke exposure leads to behavioral disturbances in rats, characterized by an increase in locomotor activity and an increased level of anxiety. Indicators of brain bioelectrical activity of the exposed animals supported the state of anxiety and psychoemotional stress. Epigenetic changes in the blood cells of exposed animals were revealed under 24 h exposure to peat smoke, characterized by a decrease in the level of global DNA methylation.

Introduction. Lead pollution is a common environmental problem. Having no physiological functions, this toxicant has a negative polytropic impact on a body, including neurotoxic, reproductive, and transgenerational effects. The mechanism of lead toxicity is oxidative stress. Flavonoids have active antioxidant properties. They are widely represented in plant foods, are able to restore protective capabilities of cells and have chelating properties with respect to lead. One of the representatives of this group of substances is dihydroquercetin. The objective was to study the effect of dihydroquercetin on behavior of rats with hereditary chemical body burden exposed to lead at 60 mg/kg during 25 days. Materials and methods. We studied the behavior of rat offspring in an open field and established their blood lead levels by electrothermal atomization atomic absorption spectrometry. For statistical processing the U-Mann – Whitney test was used. Results. In the present experiment, the effect of lead on the offspring of male albino rats exposed to 60 mg/kg of lead for 25 days caused changes in the activity of animals in the open field. The severity of changes was more pronounced in animals with a hereditary chemical body burden. These animals showed a decrease in orientation and physical activity and increased anxiety. In rats with a hereditary burden, changes in behavior were detected when administering dihydroquercetin. The activity of animals demonstrated a positive dynamics: we observed a statistically significant increase in physical activity and orientation. The number and duration of behavioral acts approached control values. Conclusions. The revealed effects of lead on the offspring of albino rats with a transgenerational chemical body burden require further study to understand the mechanism of the phenomenon.

Experimental studies of Perchlozone, an antituberculous drug with manifest inhibitory activity towards Mycobacterium tuberculosis and Mycobacterium bovis, were carried out. Genotoxicity of Perchlozone was evaluated by the DNA comet method on liver and lung tissues and blood cells after 14-day inhalation exposure of rats. The level of DNA aberrations in response to inhalations of the drug in a concentration of 102.6±13.7 mg/m3 increased in lung tissue but not in the blood cells or liver. These results indicated genotoxic activity of antituberculous drug Perchlozone.

The contribution of prenatal hypoxic damage to the CNS to the formation of high sensitivity of the body to lead acetate was studied. Prenatal fetal hypoxia was modeled by the administration of sodium nitrite in doses of 5, 25, and 50 mg/kg to pregnant female rats. Cognitive capacities of mature offspring were evaluated in the radial maze test and Morris water maze test. After attaining learning criterion in the radial maze, lead acetate in a dose of 80 mg/kg was added to the drinking water of all animals over 2 weeks. Testing was performed during the exposure to the agent until disruption of the conditioned behavior. It was found that severe prenatal hypoxia (induced by the administration of 50 mg/kg sodium nitrite) impaired spatial memory, increased latency of funding the platform in Morris water maze test, and serves as a factor contributing to earlier manifestations of the neurotoxic effects of lead acetate.

The effect of lead on the body causes damage in various systems - dysfunctions of blood formation, the cardiovascular system, liver and kidneys, brain, the male reproductive system and DNA damage. The article aims to identify the lead intoxication effect on the offspring of the first generation of male rats. Male albino rats received daily lead acetate with drinking water during 25 days (60 mg/kg) Animals were examined in the open field; the hemoglobin content in the blood was determined. The statistical analysis using the U-Mann-Whitney test was carried out. Behavior changes in the offspring from males intoxicated with lead were identified. In the offspring without transgenerational load, no changes in behavior were identified. The hemoglobin content in all groups of animals did not differ from control values. The manifestations of lead intoxication are influenced by the duration of intoxication and the internal state of the body. The mechanisms of this phenomenon require further studies.

Introduction. Lead is one of the priority factors of the environment, highly hazardous to human health and causing the greatest concern due to the accumulation in the environment. The paper presents the results of the studying the influence of lead on genotoxicity and motor activity of posterity of white rats obtained from males exposed to lead acetate. The aim of the study was to explore the effects of lead acetate action on the behavior of the offspring of the first two generations of male albino rats and to reveal the genotoxic effect. Material and methods. Male albino rats received daily lead acetate with drinking water for 7 weeks (60 mg/kg). Obtained after mating with intact females first generation offspring (males) were tested in an “open field” and the presence of DNA comets in the sex cells of the testes and nervous tissue was determined. Then the males were exposed to lead acetate in the same dose and after mating with intact females, the male offspring of the second generation was tested according to a similar scheme. In all animals receiving a lead, its content in blood and testes was determined. Results. The results of the conducted research showed that under the influence of lead acetate on male rats, the transgenerational effect was manifested in animals of the first two generations in the form of changes in the structure of behavior having a different orientation - a decrease in motor and research activity in the first generation and an increase in the second generation. The DNA comet study revealed no DNA damage in sperm cells in animals exposed to lead neither in their offspring. Along with this, the results of the study of the degree of DNA damage in animal brain cells showed a significant increase in DNA damage in the first generation after the exposure to lead. Discussion. The effect of lead acetate on adult male albino rats leads to the formation of disturbances in motor and research component of behavior and also causes an increase in DNA damage in brain cells in first and second generations.

Ртуть обладает гонадотропным и мутагенным действием на организм млекопитающих. Данный факт указывает на возможность появления эффектов воздействия ртути на потомков, чьи родители контактировали с данным токсикантом. Изучено воздействие сулемы на развитие потомства первого поколения, полученного от самцов и самок аутбредных крыс, подвергавшихся воздействию данным веществом. В течение шести недель аутбредным крысам обоего пола подкожно вводили раствор сулемы (0,05 мг ртути на 100 г массы тела животного). После окончания инъекций крысы спарены с интактными особями для получения потомства. Обследование потомства белых крыс проводилось в два этапа. Первый – изучение развития сенсорно-двигательных реакций в первый и десятый дни жизни. Второй этап включал исследование зоосоциального поведения и активности в открытом поле особей, достигших половой зрелости. Также производили взвешивание потомства с целью оценки физического развития. Полученные материалы исследований обрабатывали с использованием методов непараметрической статистики (U-критерий Манна – Уитни). При анализе результатов эксперимента выявлены статистически значимые отличия в массе тела и двигательной активности животных опытной группы, по сравнению с контролем. В первые дни жизни у особей, полученных от опытных самцов, обнаружено уменьшение массы тела и не отмечены отличия в созревании сенсорно-двигательных рефлексов. У крысят, полученных от самок с интоксикацией сулемой, обнаружено увеличение массы тела и двигательной активности, по сравнению с контрольными значениями. У половозрелого потомства найдены изменения массы тела и поведения. При взвешивании опытных животных отмечено увеличение массы тела по сравнению с контролем. У особей, полученных от самцов опытной группы, обнаружено угнетение двигательной, ориентировочно-исследовательской и зоосоциальной активности. У потомства самок опытной группы наблюдалось угнетение двигательной и ориентировочно-исследовательской активности среди мужских особей и усиление ориентировочно-исследовательского – у женских.

This article presents the results of experimental studies of adverse effects of environmental and occupational exposures on the morphofunctional state of the central nervous system in offspring rats. The results of this study show that newborn offspring of rats exposed to vinyl chloride and mercuric chloride lagged behind the controls in sensory-motor development. There was violated the whole structure of behavior in adult offspring characterized by reduces motor and exploratory activity, increased anxiety in rats. There was abnormal impulse conduction in the neuromuscular apparatus of the hind legs of albino rats and morphological changes in the structure of nervous tissue. Developmental disorders in the offspring may be associated with the processes of accumulation, influence on the genetic apparatus of cells or mediated by epigenetic mechanisms of CNS disorders. A comparative study of the behavioral and cognitive effects of toluene, cerebral bioelectrical activity in rats with a normal embryogenesis and background prenatal hypoxia has been found that toluene neurotoxicity are more pronounced in adult rats exposed to chronic prenatal hypoxia. The results suggest a possible decrease in the sensitivity of neurons to the action of neurotoxicants because of prenatal hypoxic damage. The significance of experimental modeling is to develop approaches to personalized medicine, because knowledge of the previous prenatal pathology or neurointoxication of parents allow study of individual measures of prevention, treatment, and decisions about employment of the younger generation.

The paper provides the results of experimental studies of the impact of vinyl chloride or sublimate intoxication in male albino rats on the functional state of the nervous system of their offspring. Retarded sensorimotor development was revealed in the neonatal offspring. The pubertal offspring showed behavioral pattern disintegrity that was characterized by changes in motor activity and orientative-exploratory responses and by anxiety. There was abnormal impulse conduction in the neuromuscular apparatus of the hind legs of albino rats and morphological changes in the structure of nervous tissue.

The examination results of the sexual matured offspring of the albino rat males with vinylchloride intoxication joined with the intact females are presented in this paper. The offspring behavior was studied using the test «OPEN FIELD» and «CROSS-FORMED LABYRINTH». The pathomorphological studies have been performed. The behavior alterations have been revealed in the rat males exposed compared with the control group. In studying the sexual dimorphism in the animal behavior the behavior differences were not found to be in the males and females exposed, characteristic for the rodents. The cortex neuron disturbances of the large brain hemispheres have been revealed in the albino rats exposed.

Morphofunctional disturbances in rats affected vinyl chloride in remote period of intoxication. The presented data concern influence of inhalation impact of vinyl chloride on nervous system of white rats in remote period.

The article covers problem of experimental biologic modelling of toxic encephalopathies. The authors represent major methodic approaches to modelling, criteria and methods to evaluate pathologic condition of CNS, present results of own research in creating models of toxic encephalopathies caused by metallic mercury and vinylchloride inhalation.

Air purification unit POTOK 150MK has been designed to clean air of space vehicles from microbial contaminant. Comparison of the data of analysis of air samples collected in different periods of operation of the space station MIR and ISS reconfirmed efficiency of the unit.

Longevity of space stations is dependent on efficiency and robustness of the life support systems. The article describes the principle of operation of air decontamination system Potok 150MK intended for providing microbial safety of the orbital station environment. High quality of air disinfection and decontamination has been demonstrated aboard SS Mir and the International space station.