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.

When exposed to noise and vibration in experimental animals there was a decrease in the content of threeiodinethyronine, thyroxin and adrenocorticotropic hormone in blood plasma after 15 and 30 days of experience. An increase in loads led to an increase in the level of threeiodinethyronine and thyroxin under vibration exposure and was normalized with noise. The content of adrenocorticotropic hormone leveled in both cases.

Изменения нейрофизиологических показателей у белых крыс в постконтактный

Introduction. Experimental studies in animals have shown ultrastructural changes in hepatic sinusoidal endothelial cells, tissue hypoxia of the kidneys, changes in the activity of oxidative processes and antioxidant enzymes, the formation of bioenergetic hypoxia, cell response in the form of infiltration of both lymphoid and macrophage cells to develop due to exposure to vibration. However, there is almost no data about the status of animals’ organs in the post-contact period. Material and methods. The study was carried out in white male rats weighing 220-240 g, were exposed to 40 Hz vibration for 60 days 5 times a week for 4 hours a day. Histological and morphometric analysis was used to assess the sensorimotor cortex tissue and hepatorenal system. Results. A decrease in the total number of brain neurons, astraglial cells in rats in 30, 60 and 120 days of the post-exposure period was found. There was hyperemia in the portal and Central veins, an increase in the number of Kupffer cells in the liver tissue at the 30th, 60th, 120th day after the exposure. Decrease in the area of the Shumlyansky-Bowman capsule was recorded in the experimental rats’ kidney tissue 30 days after the end of vibration exposure; though there were no differences in the number of renal bodies in the tissue of white rats of the experimental and control groups at 60th and 120th day after the end of exposure to vibration. Conclusion. Morphological changes in the tissues of white rats exposed to prolonged vibration presented in the form of a decrease in the total number of neurons and astroglia cells in the brain tissue, a pronounced macrophage response in the liver tissue have been preserved in the post-contact period following the exposure to vibration.

The aim of the present investigation is to estimate the role of prenatal hypoxia in toluene neurotoxic effect in adult rats. Toluene-induced behavioral and electroencephalographic manifestations were investigated in animals with normal and abnormal embryonic development. To simulate prenatal hypoxia, we gave subcutaneous injections of sodium nitrite to pregnant female rats in a dose of 50mg/kg on the 18–19th day of gestation. At the age of 3months the males from the offspring were exposed to toluene inhalation (560mg/m3, 4w eeks, 4h/day, 5days/week). After toluene inhalation exposure we estimated rats’ individual behavior by plus maze test and visual and auditory evoked potentials (VEPs and AEPs). Toluene reduced P2N2 interpeak amplitude of VEPs compared with control rats without any latency change. We found out that toluene exposure of rats with acute prenatal hypoxia in late gestation had led to inhibition of motor activity and a statistically significant increase in latency of VEP’s N1, AEP’s P3 and N1P2 interpeak amplitude of AEP in comparison with all remained groups. Thus, these results show that prenatal hypoxic damage to the central nervous system is an aggravating factor in toluene intoxication in rats.

Comparative study covered influence of toluene on behavioral parameters, cognitive abilities and brain bioelectric activity in white rats with normal embryonic development or with prenatal hypoxia. Prenatal hypoxia was simulated by subcutaneous injection of 50 mg/kg sodium nitrite into female white rats on day 13-14 of gestation. The offspring at the age of 2, 5-3 months was exposed to toluene (concentration of 560 mg/m3, 4 hours per day, 5 days per week, over 4 weeks). After the exposure, the animals were estimated for individual and intraspecific behaviour in "open fields and "resident-intruder" tests, for cognitive abilities in "radial maze" training, EEG with visual and auditory evoked potentials. Acute hypoxia at early stages of organogenesis appeared to be burdening factor and to influence consequences of toluene intoxication.

The authors presented results of experimental studies assessing influence of vibration on white rats. Dynamics of morphologic changes development in brain of experimental animals exposed to vibration were shown. Exposure to vibration in white rats daily during 4 hours over 15 days causes astrogliosis--compensation process in response to brain injury; over 1 month--causes morphologic brain changes (vacuoles formation in neuropile, decrease in astroglia cells number); over 2 months--causes lower plasticity of brain neurons, preserved astrogliosis; over 4 months--causes perivascular edema. Changes in brain bioelectric activity indicate stages of pathologic process in central nervous system. Increase in vibration exposure duration leads to more severe diffuse pathologic changes in brain and local cortical and diencephalic disorders. Exposure to vibration in white rats causes increase in general mobility, nonspecific activation of behaviour, intense emotional exertion, negative emotional state, but less severe effects of vibration were seen in orientative-trying reactions that are inborn, inherited forms of behaviour.

The article presents the results of experimental studies on the effects of noise on the body of white rats. That long-term exposure to noise (1, 4 months) leads to an increase in slow-wave activity, as well as changes in visual and auditory cortical response, with an increase in latency and a decrease in the amplitude values of the main peaks, indicating that the stress response of animals to the stimulus. Additionally, chronic exposure leads to noise reduction in general motor activity, increased anxiety, reduced emotional activity animals. Pathological examination revealed a violation of the vascular nature when exposed to noise for 15 days, longer duration of action of factor causes irreversible changes in the nervous tissue in the form of reduction in the total number of neurons per unit area, the presence of glial scarring in the area of 2 layers of the cerebral cortex, increasing the number of cells astroglia.

The hormonal and clinical-sexological examinations of 79 married males aged 29-55 years with the diagnosis of the vibration induced disease from the exposure to local vibration has been performed. During the examinations, disorders of the hormonal status as one of the causes of the sexual disorder as well as the alterations in sexual constitution have been revealed. Dependence of the working period duration on the hormone levels, dependence of the degree of the vibration-induced disease expression on the testosterone level in blood as well as dependence of the level of thyreoid hormones on sexual constitution have been established.

The hormonal and clinical-sexological examinations of 79 married males aged 29-55 years with the diagnosis of the vibration - induced disease from the exposure to local vibration has been performed. During the examinations, disorders of the hormonal status as one of the causes of the sexual disorder as well as the alterations in sexual constitution have been revealed. Dependence of the working period duration on the hormone levels, dependence of the degree of the vibration-induced disease expression on the testosterone level in blood as well as dependence of the level of thyreoid hormones on sexual constitution have been established.

The materials of the long-studies among the employees working in the aircraft industry, of both the patients with occupational diseases and the practically healthy persons are discussed in the paper. Using the method of the biological feedback for the vibration-induced disease prevention has been grounded. The preliminary results of the experimental studies using the animals are presented in this paper.

Patients with vibration-induced disease (VID), induced by local vibration are surveyed. Studied parame-ters of functional-metabolic status of neutrophils (activity of phagocytosis, alkaline and acidic phos-phatase, the maintenance of glycogen) and the hormonal status (a level of thyroxine, triiodothyronin and cortisol in blood Serum). It is established, that at patients with VID while intensifying gravity of patho-logical process decrease the activity of alkaline phosphatase and maintenance of glycogen in neutrophils is marked. Thus it is not taped dependences of triiodothyronin level depression and functional activity of neutrophils from a degree of disease expression.

The dynamics of hormonal parameters changes in workers of noise dangerous occupations was studied over 5 year period. It was shown that with extension of length of service the content of hormones in peripheral blood of patients with sensorineural deafness has not changed significantly.

In studying of hormonal status in the patients with vibration-induced disease due to exposure to a local vibration during 9 years the one-directed changes in hormonal indices, manifested as the decrease in ACTH, cortisol and triiodotyronine levels have been revealed. At the same time, hormone content in the peripheral blood has not significantly changed in the same subjects with vibration-induced disease with increase in the work length. This is probably correlated with «hyroscopic effect» of endocrine system.