Animal models are an important tool for studying ischemic mechanisms of stroke. Among them, the middle cerebral artery occlusion (MCAO) model via the intraluminal suture method in rodents is closest to human ischemic stroke. It is a model of transient occlusion followed by reperfusion, thus representing cerebral ischemia-reperfusion model that simulates patients with vascular occlusion and timely recanalization. Although reperfusion is very beneficial for the possibility of preserving brain functions after ischemia, it also brings a great risk in the form of brain edema, which can cause the development of intracranial hypertension, and increasing morbidity and mortality. In this paper, we present the results of our own transient reperfusion model of MCAO in which we tested the permeability of the blood-brain barrier (BBB) using Evans blue (EB), an intravital dye with a high molecular weight (68,500 Da) that prevents its penetration through the intact BBB. A total of 15 animals were used in the experiment and underwent the following procedures: insertion of the MCA occluder; assessment of ischemia by 2,3,5 -Triphenyltetrazolium chloride (TTC) staining; assessment of the BBB permeability using brain EB distribution. The results are presented and discussed. The test of BBB permeability using EB showed that 120 minutes after induction of ischemia, the BBB is open for the entry of large molecules into the brain. We intend to use this finding to time the application of neuroprotective agents via ICA injection in our next stroke model. Keywords: Cerebral ischemia-reperfusion model, Middle cerebral artery occlusion, Blood-brain barrier, 2,3,5 -Triphenyltetrazolium chloride, Evans blue.
- MeSH
- hematoencefalická bariéra * metabolismus patologie MeSH
- infarkt arteria cerebri media * metabolismus patologie MeSH
- ischemie mozku * metabolismus patologie MeSH
- kapilární permeabilita * fyziologie MeSH
- krysa rodu Rattus MeSH
- modely nemocí na zvířatech MeSH
- permeabilita MeSH
- pilotní projekty MeSH
- potkani Sprague-Dawley MeSH
- potkani Wistar MeSH
- reperfuzní poškození * metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Cerebral perfusion pressure (CPP) is the net pressure gradient that drives oxygen delivery to cerebral tissue. It is the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). As CPP is a calculated value, MAP and ICP must be measured simultaneously. In research models, anesthetized and acute monitoring is incapable of providing a realistic picture of the relationship between ICP and MAP under physiological and/or pathophysiological conditions. For long-term monitoring of both pressures, the principle of telemetry can be used. The aim of this study was to map changes in CPP and spontaneous behavior using continuous pressure monitoring and video recording for 7 days under physiological conditions (group C - 8 intact rats) and under altered brain microenvironment induced by brain edema (group WI - 8 rats after water intoxication) and neuroprotection with methylprednisolone - MP (group WI+MP - 8 rats with MP 100 mg/kg b.w. applicated intraperitoneally during WI). The mean CPP values in all three groups were in the range of 40-60 mm Hg. For each group of rats, the percentage of time that the rats spent during the 7 days in movement pattern A (standard movement stereotype) or B (atypical movement) was defined. Even at very low CPP values, the standard movement stereotype (A) clearly dominated over the atypical movement (B) in all rats. There was no significant difference between control and experimental groups. Chronic CPP values with correlated behavioral type may possibly answer the question of whether there is a specific, universal, optimal CPP at all.
Brain edema is a fatal pathological state in which brain volume increases as a result of abnormal accumulation of fluid within the brain parenchyma. A key attribute of experimentally induced brain edema - increased brain water content (BWC) - needs to be verified. Various methods are used for this purpose: specific gravimetric technique, electron microscopic examination, magnetic resonance imaging (MRI) and dry/wet weight measurement. In this study, the cohort of 40 rats was divided into one control group (CG) and four experimental groups with 8 rats in each group. The procedure for determining BWC using dry/wet weight measurement was initiated 24 h after the completion of edema induction by the water intoxication method (WI group); after the intraperitoneal administration of Methylprednisolone (MP) together with distilled water during edema induction (WI+MP group); 30 min after osmotic blood brain barrier disruption (BBBd group); after injection of MP via the internal carotid artery immediately after BBBd (BBBd + MP group). While induction of brain edema (WI, BBBd) resulted in significantly higher BWC, there was no increase in BWC in the MP groups (WI+MP, BBBd+MP), suggesting a neuroprotective effect of MP in the development of brain edema.
- MeSH
- edém mozku * chemicky indukované diagnostické zobrazování patologie MeSH
- edém patologie MeSH
- hematoencefalická bariéra MeSH
- krysa rodu Rattus MeSH
- methylprednisolon farmakologie MeSH
- mozek MeSH
- voda MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- methylprednisolon MeSH
- voda MeSH
Brain edema - a frequently fatal pathological state in which brain volume increases resulting in intracranial pressure elevation - can result from almost any insult to the brain, including traumatic brain injury. For many years, the objective of experimental studies was to find a method to prevent the development of brain edema at the onset. From this perspective, the use of methylprednisolone (MP) appears promising. High molecular MP (MW>50 kDa) can be incorporated into the brain - in the conditions of the experimental model - either by osmotic blood-brain barrier disruption (BBBd) or during the induction of cellular edema by water intoxication (WI) - a condition that increases the BBB permeability. The time window for administration of the MP should be at the earliest stages of edema. The neuroprotective effect of MP on the permeability of cytoplasmatic membranes of neuronal populations was proved. MP was administrated in three alternative ways: intraperitoneally during the induction of cytotoxic edema or immediately after finishing cytotoxic edema induction in a dose of 100 mg/kg b.w.; into the internal carotid artery within 2 h after finishing cytotoxic edema induction in a dose of 50 mg/kg b.w.; into internal carotid artery 10 min after edema induction by BBBd in a dose of 50 mg/kg b.w.
- MeSH
- edém mozku farmakoterapie metabolismus patologie MeSH
- glukokortikoidy farmakologie MeSH
- hematoencefalická bariéra účinky léků metabolismus patologie MeSH
- kapilární permeabilita účinky léků MeSH
- krysa rodu Rattus MeSH
- methylprednisolon farmakologie MeSH
- modely nemocí na zvířatech MeSH
- mozek účinky léků metabolismus patologie MeSH
- neurony účinky léků metabolismus patologie MeSH
- neuroprotektivní látky farmakologie MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- glukokortikoidy MeSH
- methylprednisolon MeSH
- neuroprotektivní látky MeSH
Magnetic resonance imaging has been used for evaluating of a brain edema in experimental animals to assess cytotoxic and vasogenic edema by the apparent diffusion coefficient (ADC) and T2 imaging. This paper brings information about the effectiveness of methylprednisolone (MP) on experimental brain edema. A total of 24 rats were divided into three groups of 8 animals each. Rats with cytotoxic/intracellular brain edema induced by water intoxication were assigned to the group WI. These rats also served as the additional control group CG when measured before the induction of edema. A third group (WIMP) was intraperitoneally administered with methylprednisolone 100 mg/kg during water intoxication treatment. The group WI+MP was injected with methylprednisolone 50 mg/kg into the carotid artery within two hours after the water intoxication treatment. We evaluated the results in four groups. Two control groups (CG, WI) and two experimental groups (WIMP, WI+MP). Rats were subjected to MR scanning 24 h after edema induction. We observed significantly increased ADC values in group WI in both evaluated areas - cortex and hippocampus, which proved the occurrence of experimental vasogenic edema, while ADC values in groups WIMP and WI+MP were not increased, indicating that the experimental edema was not developed and thus confirming the protective effect of MP.
- MeSH
- antiflogistika farmakologie MeSH
- edém mozku diagnostické zobrazování farmakoterapie patologie MeSH
- hipokampus diagnostické zobrazování účinky léků MeSH
- krysa rodu Rattus MeSH
- magnetická rezonanční tomografie metody MeSH
- methylprednisolon farmakologie MeSH
- modely nemocí na zvířatech MeSH
- mozek diagnostické zobrazování účinky léků MeSH
- mozková kůra diagnostické zobrazování účinky léků MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antiflogistika MeSH
- methylprednisolon MeSH
OBJECTIVE: Experimental lesions in the inferior alveolar nerve (IAN) are used for the study of peripheral and central alterations. The objective of our study was to contribute to a more precise description of the approach to the IAN and creating a lesion. MATERIAL AND METHODS: Twenty-six males of Wistar laboratory rats were used for the study. The animals were divided into three groups: control group (6 rats), experimental group (12 rats - a part of the bone above the mandibular canal was removed under general anaesthesia using extraoral approach, after exposing a part of the IAN, the nerve was excised in a length of 3 mm), and a sham group (8 rats - the nerve was only dissected but not transected). Persisting denervation was verified using surgical revision and histological and immunohistochemical analysis after the observation period (4 weeks). RESULTS: No evidence of re-innervation after 4 weeks. We found no statistically significant differences in mean weight gains between individual groups during the observation period. CONCLUSION: The described technique used in the study is one of the possible ways to create a nerve lesion at the site of the main trunk of the nerve. At the same time, the study provides a more precise description of the anatomical situation and approach to the IAN in the mandibular canal.
- Klíčová slova
- Nervus alveolaris inferior, laboratory rat, nerve transection technique, neuroanatomical study,
- MeSH
- denervace metody MeSH
- krysa rodu Rattus MeSH
- modely u zvířat MeSH
- nervus mandibularis patofyziologie chirurgie MeSH
- neuroanatomie MeSH
- potkani Wistar MeSH
- regenerace nervu fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
Self-assembly is an attractive phenomenon that, with proper handling, can enable the production of sophisticated hybrid nanostructures with sub-nm-scale precision. The importance of this phenomenon is particularly notable in the fabrication of metal-organic nanomaterials as promising substances for spintronic devices. The exploitation of self-assembly in nanofabrication requires a comprehension of atomic processes creating hybrid nanostructures. Here, we focus on the self-assembly processes in the vapour-deposited Au x C60 mixture films, revealing the exciting quantum plasmon effects. Through a systematic characterization of the Au x C60 films carried out using structure-sensitive techniques, we have established correlations between the film nanostructure and the Au concentration, x. The analysis of these correlations designates the Au intercalation into the C60 lattice and the Au clustering as the basic processes of the nanostructure self-assembly in the mixture films, the efficiency of which strongly depends on x. The evaluation of this dependence for the Au x C60 composite nanostructures formed in a certain composition interval allows us to control the size of the Au clusters and the intercluster spacing by adjusting the Au concentration only. This study represents the self-assembled Au x C60 mixtures as quantum materials with electronic functions tuneable by the Au concentration in the depositing mixture.
- Publikační typ
- časopisecké články MeSH
Study of motor activity is an important part of the experimental models of neural disorders of rats. It is used to study effects of the CNS impairment, however studies on the peripheral nervous system lesions are much less frequent. The aim of the study was to extend the spectrum of experimental models of anterior limb movement disorders in rats by blockade of the right anterior limb brachial plexus with the local anesthetic Marcaine (Ma), or with aqua for injection administered into the same location (Aq) (with control intact group C). Two other groups with anterior limb movement disorders underwent induction of cellular brain edema by water intoxication (MaWI and AqWI). Results showed a lower spontaneous motor activity of animals in all experimental groups versus controls, and lower spontaneous motor activity of animals in the MaWI group compared to other experimental groups in all categories. There was no difference in spontaneous activity between the groups Ma, Aq and AqWI. Our study indicates that alterations of spontaneous motor activity may result from the impaired forelimb motor activity induced by the anesthetic effect of Marcaine, by the volumetric effect of water, as a result of induced brain edema, or due to combination of these individual effects.
- MeSH
- edém mozku komplikace patofyziologie MeSH
- intoxikace vodou komplikace patofyziologie MeSH
- krysa rodu Rattus MeSH
- modely nemocí na zvířatech * MeSH
- pohybová aktivita fyziologie MeSH
- pohybové poruchy etiologie patofyziologie MeSH
- potkani Wistar MeSH
- přední končetina patofyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Induction of cellular cerebral edema (CE) was achieved by a standard method of water intoxication which consisted of fractionated intraperitoneal administration of distilled water (DW) together with the injection of desmopressin (DP). Using metabolic cage, fluid and food balance was studied in two groups of eight animals: group C - control; group CE - cellular edema induced by water intoxication. For each rat the intake (food pellets and water) and excretion (solid excrements and urine) were recorded for 48 h together with the initial and final body weight. CE animals consumed significantly less food, drank less water and eliminated the smallest amount of excrements. The induction of cellular cerebral edema was accompanied with a significant loss of body weight (representing on average 13 % of the initial values) mainly due to a reduction of food intake. This phenomenon has not yet been reported.
- MeSH
- antidiuretika toxicita MeSH
- desmopresin toxicita MeSH
- edém mozku chemicky indukované metabolismus MeSH
- hmotnostní úbytek fyziologie MeSH
- intoxikace vodou chemicky indukované metabolismus MeSH
- krysa rodu Rattus MeSH
- potkani Wistar MeSH
- tělesná hmotnost fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antidiuretika MeSH
- desmopresin MeSH
The original article was published in Folia Biologica (Praha) Volume 64, No. 3 (2018), 84-96.
- Publikační typ
- časopisecké články MeSH
- tisková chyba MeSH
