CHANGES IN THE SENSORIMOTOR CORTEX OF THE RAT BRAIN UNDER THE MODELING OF HEMORRHAGIC STROKE.

OBJECTIVE: The aim: To assess the structural and metabolic changes in the sensorimotor cortex of the rat brain under conditions of hemorrhagic stroke. PATIENTS AND METHODS: Materials and methods: The experiment was carried out on rats of the control and experimental groups with a model of hemorrhagic stroke. We used histological, electron microscopic, biochemical methods and biological markers. RESULTS: Results: In the sensorimotor cortex of the ipsilateral cerebral hemisphere of rats under conditions of hemorrhagic stroke, cerebral edema and progression of neurodegenerative changes were observed; an increase in the size of mitochondria, which is caused by edema of their matrix; activation of lipid peroxidation processes and a decrease in the activity of enzymes of the antioxidant system, a decrease in the level of apoptosis markers and inhibition of ERK1/2 expression. The study of DNA fragmentation in the cerebral cortex revealed a significant number of manifestations of necrosis and an insignificant number of cells in a state of apoptosis. CONCLUSION: Conclusions: after modelling a hemorrhagic stroke in the right hemisphere of the brain, perivascular and pericellular edema of the energy apparatus, cell death by necrosis and apoptosis, and activation of lipid peroxidation processes were established as well as a decrease in the activity of enzymes of the antioxidant system.

CARDIOVASCULAR SYSTEM OF THE MATURE RATS WITH CONGENITAL HYPOTHYROIDISM AND ARTERIAL HYPERTENSION.

OBJECTIVE: The aim: Studying changes in the ultrastructure of blood circulatory capillaries of the myocardium of mature rats with hypothyroidism and arterial hypertension. PATIENTS AND METHODS: Materials and methods: Experiments were conducted on (240 days) 10 ISIAH (inherited stress-induced arterial hypertension) line rats with AH (arterial hypertension), 10 Wistar line rats with congenital hypothyroidism and 10 intact animals. Arterial pressure was measured, and the development of hypothyroidism was controlled by the immune enzyme method. The study of the left ventricle myocardium of the rat heart was carried out by electron microscopic and morphometric studies. RESULTS: Results: In in rats with AH the following changes were observed in the blood capillaries of the myocardium: decrease in the number of capillaries; disturbance of blood circulation; the number of organelles of the biosynthetic plan and structures involved in the transendothelial transfer of substances decreased in endothelial cells; lysis and edema of the latter; mucinous perivascular edema, confirmed by the accumulation of fine-fibrillar structures, collagen fibers, cellular detritus. By the same term, in the group with congenital hypothyroidism, dystrophic-destructive changes in the blood capillaries of the myocardium acquired the highest degree, which resulted in a decrease in their number due to destruction. Ultrastructure of the biosynthetic plan organelles and structures of the transendothelial transfer of substances were in decompensated state. CONCLUSION: Conclusions: The rats (in 240 days) with AH and congenital hypothyroidism express breakdown of compensatory processes in the capillaries of the myocardium. This is manifested by the further dilution of capillaries, the development of hypoxic state in them as well as mucinous edema of interstitium, the decrease of activity of biosynthetic and transport processes.

INFLUENCE OF COMBINED PHARMACOTHERAPY ON CARDIO-VASCULAR SYSTEM OF ARTERIAL HYPERTENSION (IN EXPERIMENT).

OBJECTIVE: The aim: Study of the patterns of structural changes in the left ventricular myocardial capillaries of rats with arterial hypertension with combined pharmacotherapy with Bisoprolol and Thiotriazolinum. PATIENTS AND METHODS: Materials and methods: Experiments were conducted on 30 line rats with congenital stress-induced arterial hypertension: 10 animals without treatment and 10 animals with treatment. Pharmacological correction of spontaneous arterial hypertension was performed with 20 mg / kg of Bisoprolol and 50 mg / kg of Thiotriazolinum per os once a day. Pharmacotherapy began at 5 months of age, that is, at a time when compensated heart failure was formed in rats with arterial hypertension. Animals were withdrawn from the experiment 100 days after the start of the correction. Control was provided by intact animals (10 rats) of the corresponding age. While extracted from the experiment rats of all experimental groups had their arterial pressure measured using a plethysmograph, 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: Results: In rats with arterial hypertension after application of Bisoprolol and Thiotriazolinum, arterial pressure significantly decreases in experimental rats compared to animals without correction. The number of capillaries in the myocardium after pharmacotherapy increases up to control values, which shows their reparation. In most endothelial cells, organelles retain their integrity and presence that are characteristic of intact rats. The well-expressed processes of transcytosis are shown by the statistical similarity of the quantitative density and the size of the micropinocytotic vesicles in the endothelial cells of the myocardium capillaries of compared experimental animals. CONCLUSION: Conclusions: In rats with arterial hypertension, the combination of Bisoprolol and Thiotriazolinum prevents the decrease in the number of capillaries in the myocardium of the left ventricle, promotes the preservation of the ultrastructure of their endothelial cells and maintains the processes of transedothelial transfer of substances at the level of intact animals.

Morphofunctional status of cardio-vascular system of rats with arterial hypertension.

OBJECTIVE: The aim: Was to clarify the general patterns of structural changes in the left ventricular myocardial capillaries in rats with spontaneous arterial hypertension. PATIENTS AND METHODS: Materials and methods: Experiments were conducted on 50 ISIAH (inherited stress-induced arterial hypertension) line rats with arterial hypertension: 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. 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: Results: In sexually mature rats with arterial hypertension, a high level of pressure is maintained. In 45-day-old rats with arterial hypertension in endothelial cells of myocardial blood capillaries there is a hyperactivation of biosynthetic processes (euchromatic nucleus, large-sized mitochondria, ER canals, Golgi complex), which may be a manifestation of reactive processes in response to a non-stable increase in arterial pressure. In the 100-day rats with arterial hypertension, the mosaic of the ultrastructure of the myocardium blood vessels is preserved, but destructively-dystrophic changes become more expressive and involve not only the organelles but also the integrity of the endothelial cell itself. Destructively-dystrophic processes in rat capillaries are accompanied by compensatory and adaptive ones. This is manifested by activation of the transport of substances, both transendothelial and paracellular, and quantitative density of micropinocytotic vesicles increases statistically significantly. CONCLUSION: Conclusions: In myocardial capillaries of young (45-day) arterial hypertension rats, compensatory and adaptive changes are manifested by activation of biosynthetic processes in endothelial cells following a slight increase in micropinocytotic vesicles quantitative density and signs of destructive-dystrophic processes (minor edema and lysis of endothelial cell cytoplasm). In sexually mature (100-day) arterial hypertension rats in the blood capillaries of the myocardium, the destructive-degenerative changes increase is accompanied by preservation of signs of compensatory processes. Reducing the number of capillaries is offset by an increase in the number of micropinocytotic vesicles.

The influence of drug treatment on cardio-vascular system of the rats with congenital hypothyroidism.

OBJECTIVE: Introduction: In the treatment of hypothyroidism substitution therapy with L-thyroxine is used, it is also advisable to use the metabolites with membrane-stabilizing properties that normalize the metabolism in the body, for example, calcitonin, which significantly reduces the depth of the dystrophic phenomena in the myocardium. The aim was to study the patterns of structural changes in the left ventricular myocardial capillaries of rats with congenital hypothyroidism in combinative drug therapy with L-thyroxine and calcitonin. PATIENTS AND METHODS: Materials and methods: 30 white Wistar line rats were used as experimental animals: 10 with treatment and 10 without as well as control - 10 intact Wistar line rats of the same age. Mercazolil was used to inhibit thyroid gland in order to model congenital hypothyroidism. After birth, the rats received L-thyroxine at a dose of 10 µg / kg per os daily, calcitonin at a dose of 1.0 MU / kg per day intramuscularly, then with mother's milk, later by themselves for 100 days. The arterial pressure was measured in all experimental groups during extraction from the experiment by plethysmograph, their left ventricular myocardium was examined under electron microscope and micropinocytotic vesicles in their cells were studied morphometrically. RESULTS: Results: In rats with congenital hypothyroidism, for which L-thyroxin drug in combination with calcitonin was used as a substitution therapy, after pharmacological correction, in general there is no pronounced heteromorphism of the ultrastructure of the left ventricular myocardial blood capillaries, which was characteristic for animals without pharmacological correction. The analysis showed normalization of the content of free thyroxine in blood plasma and blood pressure of rats with congenital hypothyroidism after complex substitution therapy. CONCLUSION: Conclusions: In rats with congenital hypothyroidism, which received L-thyroxine and calcitonin at birth, the myocardium capillaries generally remain intact and have morphological and functional characteristics similar to intact animals, which is the theoretical basis for the need for calcitonin to be used in substitution therapy in hypothyroidism.

Morphofunctional status of cardio-vascular system of rats with congenital hypothyreosis.

OBJECTIVE: 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. PATIENTS AND METHODS: 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: 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. CONCLUSION: 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.