Lead as any heavy metals may be found in soil, water, air, and is used in everyday life. Once in the body, it causes toxic effect, making the liver, which is one of the main organs of detoxification, suffer. Recently, the study of the action of not only ionic forms of lead, but also its nanoparticles, has become topical. The study aims at determining changes in the liver of rats and biochemical changes in their blood both at late term of exposure to nanoparticles of lead compounds and in the post-exposure period. The study was performed on 120 male rats of Wistar line, which were divided into two series, each series containing four groups. The first and the second groups of animals were intraperitoneally injected with colloidal solution of nanoparticles of lead sulfide of 10 and 30 nm in size, and the third group were intraperitoneally injected with a solution of lead nitrate. The fourth group of animals served as control. In the first series, the investigated substances were administered 60 times within 12 weeks. In the second series, after 60-fold administration of the investigated substances, the exposure was discontibued and animals were observed for 6 weeks-overall duration of 18 weeks. Histological, morphometrical and biochemical methods were used. The body weight was reduced in the rats exposed to PbS at week 12 of experiment and in rats exposed to both PbS and Pb(NO ) in the second series. Absolute liver weight increased at week 12 of experiment in all experimental groups. In the second series this value almost reached that of the control level. Relative liver weight in the animals of all experimental groups was higher than that in the control at week 12 of experiment. In the second series this value remained higher in rats exposed to PbS . After 12 weeks of exposure dystrophic changes in the liver were found in all experimental groups. At week 6 after the exposure (the second series) destructive changes in the liver decreased. Total protein, albumin, glucose, total lipids, cholesterol, triglycerides content in blood serum corresponded with morphological data. The experiment has demonstrated that the 12 weeks long exposure to lead nanoparticles had harmful effect on the liver. Within the postexposure 6-weeks period structural changes in the liver and biochemical changes in blood serum decreased. Biochemical changes in blood serum corresponded to the morphological data. By many parameters PbS had more pronounced harmful effect. Toxicity of PbS and Pb(NO ) were comparable.

Morphological data show that unithiolum and thiotriazolinum action decreases toxic effects of mercury chloride and are similar. They demonstrate pronounced activation of synthetic processes in sensory neurons and satellite cells of spinal ganglia. Mildronate also restores cell ultrastructure and has more pronounced effect on their energetic processes and interaction between neurons and satellite cells.

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Introduction: There is an increasing number of cases of congenital hypothyroidism. One of the most common complications of hypothyroidism is damage to the cardiovascular system, which in 30-50% of patients leads to the development of arterial hypertension. The aim: studying the features of the ultrastructure of myocardial capillaries in mature rats with hypothyroidism. Materials and methods: Experiments were conducted on 40Wistar line rats with congenital hypothyroidism: juvenile young (45-day) and sexually mature (100-day) rats, as well as intact animals of the corresponding age. While extracted from the experiment rats of all experimental groups had their arterial pressure measured using a plethysmograph while the development of hypothyroidism was controlled by the immune-enzymatic method. Electron microscopic examination of the left ventricular myocardium and morphometric study of volumetric and quantitative densities, cross-section area, and form factor of micropinocytotic vesicles were conducted. Results: In the sexually mature rats with congenital hypothyroidism the quantitative density of the capillaries in the myocardium decreases. Activation of transcytosis is accompanied by significant violations of vesiculation. Some of the endothelial cells of experimental animals contain a moderate amount of transport vesicles, while others are overfilled with these structures and desquamate into the lumen. In older rats with congenital hypothyroidism there is a further dilution of capillaries, the development of hypoxic state in them, mucinous edema of interstitial space, decrease of biosynthetic and transport processes activity. Conclusions: In young (45-day) rats with congenital hypothyroidism the direction and expressiveness of compensatory processes is to enhance the transcytosis processes. Dystrophicdestructive changes are manifested by apoptosis in some endothelial cells, decrease in the number of biosynthetic organelles, lysis and edema of their cytoplasm. In sexually mature (100-day) rats with congenital hypothyroidism destructively-dystrophic processes in the blood capillaries of the myocardium are approximately balanced with compensatory-adaptive.

Cardiovascular diseases are the leading cause of death and disability worldwide. It has been established that in recent years there has been a significant increase in the number of patients with this pathology, forcing researchers, scientists and physicians to look for risk factors of cardiovascular diseases, one of which is hyperhomocysteinemia (HHCys). The aim of the research is to study the features of submicroscopic changes in the heart of adult rats under conditions of HHCys. Experimental studies were performed on 22 white nonlinear adult (6-8 months) male rats in accordance with the principles of bioethics (Strasbourg, 1986; Kyiv, 2001). During the experiment, the animals were divided into two groups – control and experimental. Simulation of persistent HHCys was achieved by administering to rats the experimental group thiolactone homocysteine (HCys) at a dose of 200 mg/kg body weight intragastrally for 60 days. Ultrathin sections were studied in the PEM – 125K electron microscope. It was found that the introduction of thiolactone HCys to adult rats at a dose of 200 mg/kg causes the development of dystrophic and destructive changes in the heart of animals. Significant connective tissue edema was observed in the endocardium, and disturbances in the components of the microcirculatory tract were detected in the myocardium. Local enlightenment, cytoplasmic edema and local condensation of heterochromatin in hypertrophied nuclei were detected in hemocapillary endothelial cells. In cardiomyocytes, myofibrils are thickened, mitochondria are swollen with partial destruction of the cristae, tubules of smooth endoplasmic reticulum and T-tubules are dilated. These findings indicate that in adult rats HHCys caused the development of pathological changes in the endocardium, myocardium of experimental animals and in the microcirculatory tract.