Experimental Hemorrhagic Stroke Research Articles

Investigation of Taurine Derivative Magnesium-Bis-(2-Aminoethanesulfonic)-Butadioateon Alleviation of Neurological Defects in Simulated Hemorrhagic Stroke in Rats.

Stroke or ischemia is caused by a blockage in a specific blood vessel that partially or completely reduces the blood flow to the brain. Nutritional factors such as antioxidants and healthy eating patterns are important variables in preventing stroke. Molecular composition properties such as molecular binding and screening can be used to evaluate the specific activity and morphological changes. The present study aimed to evaluate the effectiveness of pharmacological correction of the consequences of a hemorrhagic stroke in rats with a new derivative of taurine magnesium-bis-(2-aminoethanesulfonic)-butadioate. The animals (n=170) were divided into four groups as follows: 1) control group (n=20), 2) group 2 suffered a hemorrhagic stroke without pharmacological correction (n=50), 3) group 3 (n=50) underwent simulation of hemorrhagic stroke received Taurine at the dose of 50 mg/kg, 4) Group 4 underwent simulation of hemorrhagic stroke with correction of hemorrhagic stroke with magnesium-bis-(2-aminoethanesulfonic)-butadioate at the dose of 150 mg/kg (LKHT 3-17) (n=50). Hemorrhagic stroke was induced by transfusing autologous blood into the parietal lobe of the right hemisphere of the brain. Lethality, neurological status, locomotor, and exploratory behavior, as well as the morphological pattern of the brain damage, were assessed on the 1st, 3rd, and 7th days after the pathology simulation. Neurological deficit was determined in animals by the McGrow stroke index scale. The locomotor and exploratory behavior was evaluated using the Acti-track software and hardware complex. Two criteria were considered when assessing morphological changes in the brain: the average thickness of the cerebral cortex (in micrometers) and the number of neurons without degenerative changes. LKHT 3-17 (150 mg/kg) and taurine (50 mg/kg) reduced lethality by 1.7 and 1.36 times, respectively, on the 3rd day after stroke compared to that of the control (p<0.05). In parallel, a neurological deficit was effectively corrected LKHT 3-17 and taurine to 5.3±0.8 and 6.5±0.9, respectively, on the 1st day in contrast to the control of 8.1±0.7 points. The locomotor and exploratory behavior was significantly different on the 7th day and was accompanied by a significant increase in total activity under the influence of LKHT 3-17 to 491 conventional units (CU) compared to the control of 110 conventional units. On the 1st day, the thickness of the cortex was 1943.7±44.08 µm, and 1491.0±38.61 µm in the control and LKHT 3-17 groups, respectively. The number of neurons without neurodegenerative changes prevailed in LKHT 3-17 group (18.7±4.32), and the lowest number was observed in the group without pharmacological correction of the pathology (14.3±3.78). The taurine derivative magnesium-bis-(2-aminoethanesulfonic)-butadioate, which is a combination of the amino acid, magnesium ion, and succinic acid, decreases the neurological deficits, lethality, and enhances the locomotor and exploratory behavior in experimental hemorrhagic stroke in rats. The effect of the studied medication on the dynamics of molecular pathophysiological mechanisms occurring in the cell requires additional research.

Autonomic and cardiovascular consequences resulting from experimental hemorrhagic stroke in the left or right intermediate insular cortex in rats.

Damage to the insular cortex (IC) results in serious cardiovascular consequences and evidence indicates that the characteristics are lateralized. However, a study comparing the effects of focal experimental hemorrhage between IC sides was never performed. We compared the cardiovascular, autonomic and cardiac changes produced by focal experimental hemorrhage (ICH) into the left (L) or right (R) IC. Wistar rats were submitted to microinjection of autologous blood (ICH) or saline (n=6 each side/group) into the R or L IC. Blood pressure (BP), heart rate (HR) and renal sympathetic activity (RSNA) were recorded. Measurements of calcium transient and sarcoplasmic Ca2+ ATPase expression in cardiomyocytes were performed. ICH increased baseline HR (Δ:L-ICH 452±13 vs saline 407±11bpm; R-ICH 450±7 vs saline 406±8bpm, P<0.05) without changing BP. HR was restored to baseline levels after i.v. atenolol. Strikingly, ICH rats presented a reduced baseline RSNA (Δ:L-ICH 122±4 vs saline 148±11spikes/s; R-ICH 112±5 vs saline 148±7spikes/s, P<0.05). After 24h of ICH we observed a marked increase in cardiac ectopies and this number was greater after ICH R-IC. Heart weight, calcium amplitude and SERCA expression were reduced only in ICH R-IC. Focal stroke into IC can alter the cardiac and renal autonomic control. Damage to the R-IC produces a greater number of arrhythmias and changes in calcium dynamics in cardiac cells indicating that the cardiovascular consequences are hemisphere-dependent. These findings confirm asymmetry for cardiac autonomic control at the IC and help to understand the cardiac and renal implications observed after specific side cortical damage.

Neurological status and structural changes in the tracheal lymphoid tissue in rats with different resistance to emotional stress of experimental hemorrhagic stroke

To study neurological status and structural changes in the tracheal lymphoid tissue in rats with different resistance to emotional stress in experimental hemorrhagic stroke. Evaluation of neurological deficit on the Menzies scale and a histological study of structural features of tracheal lymphoid tissue were performed on days 1, 3 and 7 of experimental hemorrhagic stroke in 98 Wistar male rats with different resistance to emotional stress. Stroke simulation was preceded by animal testing to determine individual stress resistance. Neurological disorders are more pronounced in non-stress-resistant animals during all periods of observation. Lymphoid nodules of the tracheal wall of rats react with destruction of lymphoid cells and depletion of small lymphocytes observed in stress-resistant rats already on the 1st day of a stroke. On the 3rd day, the neurological deficit and changes in the cellular composition of the lymphoid formations of the trachea are most pronounced in both groups of rats. By the 7th day, a positive trend towards the restoration of the structure of tracheal lymphoid tissue and normal neurological status is detected only in rats resistant to emotional stress.

Structural changes in liver under conditions of experimental hemorrhagic stroke

Abstract The article describes the results of histological and morphometric studies of liver in Balb/c mice with hemorrhagic stroke. The hemorrhagic stroke was modeled in the animals by administering autoblood in volume of 0.1 ml in the right hemisphere, and within 5, 10 and 30 days an analysis of structural changes in the liver was performed. Progressive changes were established in terms of 5-10 days of the experiment. This consisted of changes in the sinusoidal capillaries and notable changes in the central veins of the liver lobuli. Herein, acute dilatation and erythrocytal stasis were most pronounced around the lumen of the central veins, while hepatocytes with signs of necrosis (severe cytoplasmic swelling, vacuolar dystrophic changes) were detected in the sinusoid capillaries. The results of the morphometry indicated an increase in the area of the nucleus and the cells caused by intracellular swelling, domination of euchromatin and decrease of total density of chromatin in nuclei. Partial regression of the diameter of sinusoidal capillaries and the area of hepatocytes were detected on the 30th day of the experiment. The changes in the sinusoidal capillaries of the liver lobules are assessed as secondary to stroke, as well as to changes in organ microcirculation, and are associated with dystrophic changes in the hepatocytes.

Neurological Deficit and Structural Changes in Lymphoid Structures of the Tracheal Wall in the Immediate Stage of Experimental Hemorrhagic Stroke in Rats with Different Behavioral Activity.

Specific features of neurological deficit and changes in the cellular composition of tracheal lymphoid structures during the immediate stage (day 1) of hemorrhagic stroke were studied in rats with various behavioral parameters. Modeling of hemorrhage in the left caudate nucleus of the brain was followed by the development of motor disturbances in the forelimb use asymmetry test and corner rotation paradigm. These animals preferred to use the left forelimb (ipsilateral to the side of hemorrhage) to lean on the cylinder wall. The frequency of using the right forelimb or both forelimbs was reduced under these conditions. The number of left-sided rotations increased, while the percentage of right-sided rotations decreased. The observed changes were accompanied by immune dysfunction. It was manifested in the depletion of lymphoid aggregates of the tracheal wall in lymphocytes and plasma cells. The severity of abnormal neurological symptoms and disturbances in immune homeostasis during the immediate stage of hemorrhagic stroke was greater in behaviorally passive rats than in active specimens.

SENSITIVITY OF RAT BRAIN SENSORIMOTOR CORTEX NEURONS TO MEDIATORS IN HEMORRHAGIC STROKE

The problem of post-stress disorders of cerebral circulation, the most severe of which is cerebral hemorrhage, or hemorrhagic stroke, is extremely urgent. Concerning the survival rate, previous studies have shown that in the same type of conflict situations, individuals resistant and predisposed to emotional stressful influences are clearly distinguished. However, the neural mechanisms providing neuromediatory regulation of responses to stressful effects are still little studied. The analysis of neurochemical sensitivity to acetylcholine and norepinephrine of the sensorimotor cortex neurons of rats having different activity according to behavior parameters, i.e., resistance to emotional stress influences before and after experimental hemorrhagic stroke (EHS) was carried out. The recovery process after an EHS due to neural activity in prognostically stable (VA) and predisposed (NA) to stressful situation rats has individual characteristics. Acute stress influence before EHS development changes the nature of neurons activity of the sensorimotor cortex in VA and NA rats on the third and seventh day after EHS. EHS leads to specific changes in the sensitivity of neurons to acetylcholine and norepinephrine in VA and NA rats. Acetylcholine microionophoresis causes activation of the neuron impulse activity in VA and NA rats, and these changes are the same after EHS. Acute stress influence before EHS development does not change nature of neuron responses to norepinephrine microionophoresis in VA animals. On the contrary, in NA rats loss of neuron sensitivity to norepinephrine during EHS development against stress was noted. It is possible that acute stress influence before EHS development can change brain noradrenergic system activity in NA rats, which are prognostically predisposed to stress influences. The data obtained stress the plasticity of the central nervous structure in development of response to stressful influences. (The ethics commission approval protocol number is 18-15 from 13th of Marth 2018.)

Acetazolamide Mitigates Intracranial Pressure Spikes Without Affecting Functional Outcome After Experimental Hemorrhagic Stroke

Increased intracranial pressure (ICP) after stroke can lead to poor outcome and death. Novel treatments to combat ICP rises are needed. The carbonic anhydrase inhibitor acetazolamide diminishes cerebrospinal fluid (CSF) production, reduces ICP in healthy animals, and is beneficial for idiopathic intracranial hypertension patients. We tested whether acetazolamide mitigates ICP elevations by presumably decreasing CSF volume after collagenase-induced striatal hemorrhage in rats. We confirmed that acetazolamide did not adversely affect hematoma formation in this model or physiological variables, such as temperature. Then, we assessed the effects of acetazolamide on ICP. Lastly, we tested the effects of acetazolamide on behavioral and histological outcome. Acetazolamide reduced the magnitude and occurrence of short-timescale ICP spikes, assessed as disproportionate increases in ICP (sudden ICP increases > 10 mmHg), 1-min peak ICP, and the magnitude of spikes > 20 mmHg. However, mean ICP was unaffected. In addition, acetazolamide reduced ICP variability, reflecting improved intracranial compliance. Compliance measures were strongly correlated with high peak and mean ICP, whereas ipsilateral hemisphere water content was not correlated with ICP. Despite effects on ICP, acetazolamide did not improve behavioral function or affect lesion size. In summary, we show that intracerebral hemorrhage creates an impaired compliance state within the cranial space that can result in large, transient ICP spikes. Acetazolamide ameliorates intracranial compliance and mitigates ICP spikes, but does not improve functional outcome, at least for moderate-severity ICH in rats.

Иммуноморфологические особенности острейшего периода экспериментального геморрагического инсульта (обзор экспериментальных морфологических исследований)

Иммуноморфологические особенности острейшего периода экспериментального геморрагического инсульта (обзор экспериментальных морфологических исследований)

Cellular composition of lymphoid nodules in the trachea wall in rats with different resistance to emotional stress in a model of hemorrhagic stroke

To reveal regularities of changes in cellular composition of lymphoid nodules in the tracheal wall in male Wistar rats resistant and not resistant to emotional stress in a model of hemorrhagic stroke. Lymphoid formations of the tracheal wall (an area near the bifurcation of the organ) were investigated in 98 male Wistar rats using histological methods. Significant changes in the cellular composition of lymphoid nodules were found. The pattern of changes depends on the stress resistance of rats and the period of the experiment. The active cell destruction in lymphoid nodules was noted both in stress resistant and stress susceptible animals. The changes in the structure of lymphoid nodules found in the experimental hemorrhagic stroke suggest a decrease in the local immune resistance, which is most pronounced in rats not resistant to stress, that may contribute to the development of severe inflammatory complications of stroke such as pneumonia.

Pharmacotherapeutic efficiency of mitochondrin (М2) and cerebral under experimental acute hemorrhagic stroke: Influence on glial homeostasis of cerebral cortex of rats

Pharmacotherapeutic efficiency of mitochondrin (М2) and cerebral under experimental acute hemorrhagic stroke: Influence on glial homeostasis of cerebral cortex of rats

Clinical course of neurological disorders in experimental hemorrhagic stroke after treatment with interleukin-2 (ronkoleukinum)

Aim. To study the influence of recombinant interleukin-2 (Ronkoleukinum) on indicators of oxidative protein modification and severity of neurologic signs in rats with experimental hemorrhagic stroke. Methods. Oxidative protein modification (by aldehyde and carboxyl products), the survival rate, neurological deficit by McGrow Stroke-index and animal psychophysiological status were studied on the model of intracerebral hemorrhage in rats after treatment with 0.01 mg/kg of interleukin-2 (Ronkoleukinum). Results. The progression of experimental hemorrhagic stroke in rats was accompanied with typical pathophysiological signs - oxidative protein modification with following neurological and cognitive disorders, followed by death of experimental animals. Administration of interleukin-2 (Ronkoleukinum) 0.01 mg/kg hampered the processes of free radical proteins damage, therefore decreasing the mortality rate in animals with intracerebral hemorrhage. Animals that were administered interleukin-2 (Ronkoleukinum) died only during the first 24 hours after the stroke, with mortality rate significantly lower compared to controls starting form the 4th day of the experiment (р 0.05). The use of interleukin-2 (Ronkoleukinum) also statistically significantly decreased the severity of post-ischemic behavioral, neurological and cognitive disorders, improving the movement activity, psychoneurological status assessed by McGrow scale, stabilizing the memory and passive avoidance reflex recovery. Conclusion: interleukin-2 (Ronkoleukinum) can effectively prevent the formation of post-stroke neuronal disorders, so its use as a nosotropic nootropic agent seems to have a good perspective.

Effect of Emotional Stress on Biogenic Amine Content in the Sensorimotor Cortex of Rats with Experimental Intracerebral Hemorrhage

Experiments on the model of an aggressive-conflict situation were designed to study the effect of emotional stress on biogenic amine content in the sensorimotor cortex of the right cerebral hemisphere in behaviorally active and passive rats with experimental hemorrhage in the left caudate nucleus of the brain. Prior exposure to stress in active and, particularly, in passive animals was shown to modify the type of neurochemical reactions in brain tissue during modeling of intracerebral hemorrhage. As differentiated from rats with experimental hemorrhagic stroke, passive specimens of this series were characterized by a slight increase in norepinephrine content and significant elevation of dopamine level in the sensorimotor cortex on day 3 of the study. An increase in dopamine content in brain tissue of stressed active rats was observed on days 1 and 3, which corresponded to the immediate and acute stages of the post-stroke period. Variations in serotonin content in the sensorimotor cortex of animals with post-stress intracerebral hemorrhage had the same dynamics, but were less pronounced than in non-stressed rats. Our results illustrate the specific involvement of brain biogenic amines in animals with various behavioral characteristics in the adaptive and compensatory processes, which occur during various stages of experimental intracerebral hemorrhage after stress exposure.

Efficacy of a new colloidal form of low-sialylated polylactide-based erythropoietin in experimental hemorrhagic stroke in rats

The aim of the present work was to develop methods for the preparation of a nanosomal form of low-sialylated recombinant human erythropoietin (ls-rhEPO), which has neurotropic antihemorrhagic activity. Measurements were made of the sorption of erythropoietin to nanoparticles made of lactic acid homopolymer or lactic acid/glycolic acid copolymer, mean nanoparticle size, and the resistance of the resulting complex to aggregation. The most effective sorption (greater than 80%) was achieved using a copolymer with equal proportions of lactic and glycolic acids (50:50). Experiments using an intracerebral post-traumatic hematoma model in rats demonstrated that nanosomal ls-rhEPO had neuroprotective actions, based on its ability to decrease death in the experimental animals (77.8% survived, which was 40% more than in the control group). Nanosomal ls-rhEPO was found to have no effect on hematopoiesis in conditions of chronic administration.

Structural Changes in Dendritic Loci and Protective Effect of Neurotrophic Factors from the Cerebral Cortex of Animals with Favorable Outcome of Experimental Hemorrhagic Stroke

Structural changes in the sensorimotor cortex of the cerebral hemispheres were studied in rats with experimental hemorrhagic stroke in the internal capsule. Changes in the shape and decrease in the density distribution of spines on apical dendrites of layer V pyramidal neurons of the sensorimotor cortex were revealed. Some fractions isolated from the complex of neurotrophic factors of the cerebral cortex of animals with a favorable outcome of hemorrhagic stroke were shown to affect the distal and proximal dendritic loci. As differentiated from the "nonactive" fraction, the "active" fraction improved the behavior of rats surviving hemorrhagic stroke. The density distribution of spines (particularly in the distal region of apical dendrites of pyramidal neurons in layer V of the cerebral cortex) was stabilized after treatment with the "active" fraction. The "nonactive" fraction had a selective effect on the proximal loci.

Morphological Changes in Rat Tracheal Wall in Experimental Hemorrhagic Stroke

Structure of the tracheal wall of male Wistar rats was studied by histological methods on days 1, 3, and 7 after experimental hemorrhagic stroke. Signs of impaired microcirculation and lymphatic drainage were revealed at all stages of the experiment. In the acute phase of stroke (day 1), these disturbances lead to destruction of epithelial cells and their extensive desquamation, edema of the submucosa, and hemorrhages in the tracheal wall. On days 3 and 7 of the experiment, destructive changes in the mucosa membrane were still present, but swelling of mucosa lamina propria and submucosa of the tracheal wall greatly decreased, probably due to evacuation of tissue fluid excess into the lumen. We can assume that changes in the structure of the tracheal wall in experimental hemorrhagic stroke impair the barrier function of the wall, which can contribute to the development of pneumonia, a serious inflammatory complications of stroke.

Emotional stress in the development of experimental hemorrhagic stroke in rats with different levels of stress resistance

Individual behavioral characteristics in rats in an open field test characterizing their resistance to emotional stress had significant influences on the severity of neurological symptomatology in intracerebral hemorrhage. Rats predicted to be resistant to stress were characterized by faster recovery of neurological status and motor and coordination impairments by day 7 after unilateral hemorrhagic stroke in the caudate nucleus than stress-susceptible rats. Changes in vessels and neurons in the contralateral sensorimotor cortex were more marked after caudate nucleus hemorrhagic stroke in stress-susceptible animals than in stress-resistant animals, while capillary neogenesis was not seen in the former group. By day 7 of poststress hemorrhagic stroke in the caudate nucleus, stress-resistant rats, unlike stress-susceptible animals, showed compensatory mechanisms in the sensorimotor cortex contralateral to the stroke, which is evidence for the possible recovery of structures and normal neuron functioning.

Abstract 5130: Leptin Increases Perihematomal Inflammation in Experimental Hemorrhagic Stroke

Background : Leptin, one of the most alleged adipokines, exerts its tissue-protective effect in ischemic injuries by reducing apoptosis through extracellular signal-regulated kinase pathway. In this context, it may be speculated that leptin also confer beneficial effect on hemorrhagic events. However, few studies have elaborated on the association between exogenous leptin and tissue damage in experimental hemorrhagic stroke model. Methods : After inducing intracerebral hemorrhage in mouse brain via the sterotaxic infusion of collagenase, 4mg/kg or 8mg/kg of recombinant leptin or vehicle (phosphate buffered saline) was administered intraperitoneally. Brain water content, reflecting peri-hematomal edema, and hemorrhage volume were measured at 72 hours after inducing hemorrhage. Inflammatory cells expressing myeloperoxidase (MPO) or OX6 were counted at 48 hours, and western blotting for Akt, pAkt, STAT3, pSTAT3, ERK and pERK was performed at 24 hours. Results : Compared to the vehicle injected mice, exogenous leptin increased brain water contents (80.07±0.29% in vehicle group, 80.74±0.32% in 4mg/kg leptin, and 81.48±0.18% in 8mg/kg leptin; rho=0.525 and p&lt;0.01). Based on this result, all the following experiments were performed with 8mg/kg of leptin. Leptin injection also augmented infiltration of MPO-stained cells (210±8 cells/mm 3 in leptin group and 133±8 cells/mm 3 in vehicle group; p&lt;0.05) and OX6-stained cells (129±13 cells/mm 3 in leptin group and 88±10 cell/mm 3 in vehicle group; p&lt;0.05). Mean hemorrhage volume was also increased in 8mg/kg leptin group (26.83±3.22 mm 3 in leptin group and 17.98±2.73 mm 3 in vehicle group; p&lt;0.05). The expression level of phosphorylated STAT3 was significantly elevated in mice with 8mg/kg leptin injection (p&lt;0.05), however, pAkt and pERK did not augmented by induced hyperleptinemia. Conclusion : Our study documented that peri-hematomal inflammation and hemorrhage volume were increased by exogenous leptin via STAT3 pathway. These results may indicate the potentially detrimental role of leptin on hemorrhagic stroke via augmentation of inflammatory response after tissue damage.

Study of the Effects of Preparation Containing Ultralow Doses of Antibodies to S-100 Protein in Experimental Hemorrhagic Stroke

Ultralow doses of antibodies to S-100 protein increased rat survival, reduced neurological deficit, eliminated myorelaxation, and improved movement coordination and cognitive functions in rats with experimental hemorrhagic stroke; the efficiency of the preparation was not inferior to that of nimodipine. In contrast to nimodipine, ultralow doses of antibodies to S-100 protein exhibited pronounced anxiolytic properties.

Structural Characteristics of Rat Tracheal Wall and Its Lymphoid Formations in the Acute Period of Hemorrhagic Stroke

The effect of experimental hemorrhagic stroke on the structure of the wall and lymphoid formations in the lower portion of the trachea was studied on male Wistar rats. Destruction and extensive desquamation of epithelial cells, edema of the submucosa, and hemorrhages were detected in the tracheal wall. Redistribution of lymphoid cells in lymphoid structures, increase in their number in the epithelium, intensification of lymphoid cell degradation in all structures of the tracheal wall indicate disorders in local immunity.