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PL
Szczury wykorzystują w komunikacji międzyosobniczej zakres ultradźwięków. Dzwięki o częstotliwości 22 kHz są interpretowane jako sygnały alarmowe, ze względu na to, że wokalizacje w tym zakresie pojawiają się jako reakcja na bodźce awersyjne. Celem prezentowanego badania było stwierdzenie, czy warunki społeczne w jakich żyło zwierzę wpływają na tendencje do wokalizacji w sytuacji stresu. Porównywane były dwie grupy szczurów: eksperymentalna – gdzie skład grupy domowej był niestabilny, ze względu na zmiany zwierząt pomiędzy klatkami oraz kontrolna – składająca się ze szczurów mieszkających w klatkach o stałym składzie osobników. Po okresie adaptacji do warunków, pozwalającym na ukształtowanie się zachowań wynikających z relacji społecznych, szczury indywidualnie poddawane były działaniu stresora dźwiękowego, a następnie, rejestrowana była liczba i czas trwania wokalizacji. Wyniki pokazały, że stałość grupy ma znaczenie. Szczury mające stałe relacje z innymi osobnikami wokalizowały mniej od tych, które przebywały w grupach o ulegającym ciągłym zmianom składzie osobniczym. Na kształtowanie się tej zależności wpływ miała płeć zwierząt – różnice w zakresie nasilenia wokalizacji były obserwowane wyłącznie u samców.
EN
Rats communicate in the range of ultrasounds. Sounds in frequency of 22 kHz are interpreted as alarm signals since they appear as the response to aversive stimuli. The aim of presented study was to find out whether social conditions in which the animals were kept influence on the tendency to vocalize in the situation of stress. Two groups of rats were compared: experimental one – with the non-stable composition of individuals, being the result of regular mixing animals among home-cages and control – stable group in the context of rats living together in home-cages. After the adaptation period, when the social conditions had chance to shape relations among individuals, rats were individually exposed to sound stressor and then the number and duration of USV vocalizations were registered. As the results showed, stability of the group is important. Rats, which had stable relations with others vocalized significantly less than those in non-stable groups. Also the influence of sex was revealed – differences in vocalization level were observed only in males.
EN
Alterations in membrane lipid composition, particularly fatty acids content is known to result in functional and structural changes. Dietary lipids and physical activity or stress play an important role in this change. It was of interest to study the influence of swimming in different temperatures on the content of fatty acids in the phospholipids of the erythrocyte membranes of rats. Our research demonstrated a significant influence of swimming on the content of fatty acids in the phospholipids of the erythrocyte membranes of rats. These changes of fatty acids, particularly the decrease of arachidonic acid and significant increase of saturated fatty acids in the phospholipids of the erythrocyte membranes in swimming rats may be induced by oxygen radicals generated in different kinds of stress.
EN
The objective of the present study was to demonstrate the effect of dietary resistant dextrins, as potential prebiotics, on the intestinal microflora of young rats. Enzyme-resistant dextrin, prepared by heating of potato starch in the presence of hydrochloric (0.1% dsb) and tartaric (40% dsb) acid at 130ºC for 2 h (CA-dextrin). The experiment was performed on 24 Wistar male rats at 3-wk of age, divided by analogues in three experimental groups (control, starch and dextrin). Analyses determined the overall bacterial counts and the counts of Lactobacillus, Bifidobacterium, Bacteroides and Clostridium strains within the feces and cecal contents of rats using fluorescence in situ hybridization method. CA-dextrin had no effect on primary growth indicators (body weight, body weight gain, dietary consumption) or the mass of the small intestine and the cecum, but dextrins caused a reduction in pH and the concentration of ammonia within the cecal contents. That supplementation of diet with resistant dextrins had a positive effect on composition of intestinal microflora in rats. It increased the counts of Bifidobacterium and Lactobacillus strains both in the feces and in the cecum. Moreover, it reduced the counts of Clostridium and Bacteroides strains. These results may suggest that resistant dextrins exerted a prebiotic-like effect in the large intestine.
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EN
The aim of the study was to evaluate the influence of vitamin E administered intraperitoneally on the prevention of peritoneal adhesion formation in rats on the basis of macroscopic and microscopic assessment of the adhesions.Material and methods. Experimental studies were performed on 50 Sprague-Dawley male rats, which were randomly divided into 5 groups, 10 rats in a group. Experimental group I (EI) included 10 rats which had peritoneal adhesions provoked by scraping of the wall of cecum and parietal peritoneum followed by intraperitoneal administration of vitamin E in the dose of 100 mg/kg body weight. Experimental group II (EII) included 10 rats which had peritoneal adhesions provoked by surgery, without administration of vitamin E. Control Group I (CI) included 10 rats which had the abdominal cavity opened without provoking peritoneal adhesions, and vitamin E was administered. Control Group II (CII) included 10 rats which had peritoneal adhesions provoked by surgery, and then lipid based solution was administered intraperitoneally. Control Group III (CIII) included 10 rats which had the abdominal cavity only opened and closed.Groups EI, CI and CII were the subject of the drugs intraperitoneal re-injection in first, second and third day after surgery. The animals were killed during the 8th postoperative day. Macroscopic examination of peritoneal adhesions using the classification reported by Nair was performed and samples for microscopic examination were excised.Results. In group EI peritoneal adhesions were formed in 60% rats (40% weak and 20% solid). In group EII peritoneal adhesions were found in all animals (30% weak and 70% solid). Reduction of the inflammatory response and less severe fibrosis were observed in animals with intraperitoneal administration of vitamin E.Conclusion. In the study, vitamin E administered intraperitoneally to rats decreased the intensity and extensiveness of peritoneal adhesions, which was confirmed by macroscopic and microscopic examinations.
EN
Ototoxicity of cisplatin is one of the major dose limiting side effects. Cisplatin-dependent ototoxicity is known to be associated with reactive oxygen species. Protective effect of taxifolin, being a flavanone found in onions, milk thistle, French maritime, and Douglas fir bark, against cisplatin-associated ototoxicity will be examined in this study. There are no studies in the literature examining the protective effect of taxifolin against cisplatin-induced ototoxicity. 50 mg/kg taxifolin was orally administered to TXC group rats (n-6), and distilled water was orally administered as solvent to CG (n-6) and HG (n-6) groups. One hour later, 5 mg/kg cisplatin was administered intraperitoneally (i.p) to TXC and CG groups. This procedure was repeated once a day for 7 days. At the end of this period, all animals were sacrificed by high-dose anesthesia (50 mg/kg thiopental sodium) and biochemical and histopathological examinations were performed on the dissected cochlea tissue. Our biochemical test results showed that oxidant parameters were significantly increased whereas antioxidant parameters were significantly decreased in the cisplatin group (CG) compared to taxifolin (TXC) and healthy (HG) groups (P <0.0001 for both parameters). Histopathological results showed that severe cochlear vestibular membrane degeneration, dilated conjunctival blood vessels, edema and destruction developed in the cisplatin group. However, no pathological findings were found in the taxifolin-treated group except for mild degeneration and edema. This information suggests that taxifolin may be useful in the treatment of cisplatin-associated oxidative cochlear damage.
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Content available remote Inulin supplementation in rat model of pouchitis
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EN
Available data indicates potential effectiveness of prebiotic therapy in alleviating inflammation and prolonging the remission in inflammatory bowel disease. Documented successes of such therapies were the basis for this study. So far, there is no data related to the effectiveness of inulin application in symptomatic or severe pouchitis in humans or in animal model. The aim of the study was to determine the effect of inulin supplementation on the expression of intestinal inflammation and feeding efficiency in rats with induced pouchitis. Twenty-four Wistar rats were operated. After induction of pouchitis animals were randomly divided into control and supplementation groups receiving, respectively, semi-synthetic diet with or without inulin (in a lower (LD) or higher (HD) dose: 2.5 % or 5 % of total dietary content of mass) for a period of 6 weeks. Selected nutritional parameters were assessed throughout the study. Histopathological and immunohistochemical analysis of pouch mucosa specimens was also performed. The energy intake, weight gain, feeding efficiency, quality of stools were comparable in all studied groups. The intensity of inflammation (Moskovitz scale) and adaptive changes (Laumonier scale) did not differ between compared groups. The tissue expression of pro- and anti-inflammatory interleukins (IL-1α, IL-6, IL-10 and IL-12) was not different either. Inulin supplementation does not improve the quality of stools or the expression of intestinal inflammation in rats with induced pouchitis. It has no impact on the intensity of pouch adaptation or on feeding efficiency.
PL
Kiedy w 1346 r. Tatarzy oblegli Teodozję na Krymie i nie mogli jej zdobyć, postanowili sięgnąć po broń biologiczną. Katapultami wstrzeliwali za mury miasta ciała zmarłych na dżumę ludzi. Teodozja padła pod wpływem epidemii. Nie jest zatem prawdą, że za roznoszenie dżumy odpowiadały jedynie szczury – zwierzęta, które zmieniły miasta jak chyba żadne inne.
EN
A novel arylsulfonamide derivative of aryloxy(propyl)piperidine PZ-1433, has been proved to possess a preclinical activity profile appropriate for the treatment of depression and memory impairments. In the present study its pharmacological activity toward anxiety symptoms as well as its anxiolytic properties have been examined in mouse and rat models. PZ-1433 significantly increased the number of punished crossings and decreased the number of buried marbles in two tests conducted in mice. Moreover, PZ-1433 evoked anxiolytic-like activity in “conditional” anxiety paradigm in rats, meaningly increasing the number of accepted shocks in the Vogel conflict drinking test. However, it did not produce a significant anxiolytic-like effect in “unconditional” anxiety model, i.e. the elevated plus-maze test. From these results, it is likely that direct antagonism toward serotonin 5-HT7 receptors may be involved in the anxiolytic action of PZ-1433. However, in vitro detected inhibition of serotonin transporter evoked by PZ-1433, might also contribute to this effect.
EN
Background: Cholinesterase inhibitors and glutamate blockers are commonly used for the treatment of cognitive impairment in Alzheimer’s disease. The aim was to evaluate the effects of rivastigmine and memantine alone or in combination in rats with scopolamine-impaired memory. Method: 5 groups of rats were used: control, scopolamine (model), model with rivastigmine, model with memantine, and model with both drugs. Active avoidance test was performed and the number of conditioned responses, unconditioned responses and intertrial crossing were recorded. Passive avoidance tests step-through with criteria latency of reaction 180 s in the light chamber and step-down with criteria latency of reaction 60 s on the platform were done. Results: Control rats learned the task and kept it on memory tests. Scopolamine treated rats failed to perform it. The rivastigmine, memantine and its combination groups showed increased CRs during learning and memory retention tests. In both passive avoidance tests an increased latency of reaction was observed in the drug treated groups. Conclusion: The combination of both drugs rivastigmine and memantine is more effective than the use of the single drug in cognitive impaired rats. Cholinesterase inhibitors and NMDA blockers may be combined in the treatment of different kind of dementias.
EN
A fast method for visual inspection and classification of massive locomotor activity data registered from laboratory rats is presented. Positions in the home cage of one hundred rats have been constantly recorded during 90 day period using photodiodes and beam crossing method with use of custom build system. Direct inspection and comparison of classic form of actograms did not bring information for fast and easy recognition of anomalies in daily behavioural cycle. A method of obtaining fast and easy to compare locomotor activity pattern is presented. The key point of proposed method is exposition of characteristic points in the activity diagram. About 9000 actograms were inspected and classified for investigation with use of ANOVA.
EN
The aim of this study was verification whether an 8-week-long swimming exercise training would induce adaptive changes in body weight in rats and whether possible changes would depend on aquatic environment temperature and animal sex. The exercisetrained groups swam 4 minutes a day, five days a week during eight week of housing. Exercise was performed by swimming in glass tanks containing tap water maintained according to group at 5 ±2°C (cold group) and 36 ±2°C (thermal neutral group). Before and after each week of the experiment, rats were weighed. When comparing the nature of changes in the body weight of rats exposed to swimming exercise training in cold water, attention should be paid to their dependence on sex. There were statistically significant changes in the nature of changes in body weight between male rats and female rats of the cold group (5°C) as early as experimental week 2 until the end of the experiment (p < 0.001). Interestingly, the females exposed to swimming exercise training at 5°C were the only group in which an increase in body weight occurred during experimental week 8 in relation to baseline values.
EN
Prebiotics are defined as selectively fermented food ingredients that induce specific changes in the composition and/or activity in the gastrointestinal microbiota beneficial to the host well-being and health. The aim of the presented experiment was to investigate the effect of a prebiotic applied alone or in combination with Hyppocastani extractum siccum, and Lini oleum virginale in rats with dimethylhydrazine induced colon cancer. Wistar albino rats were fed high fat diet supplemented with the prebiotic alone or in combination with Horse chestnut and flaxseed oil. The activity of faecal glycolytic enzymes, lipid parameters, bile acids, short chain fatty acids and counts of coliforms and lactobacilli were determined. Treatment with the prebiotic alone and in combination with selected substances significantly decreased the activity of glycolytic bacterial enzyme β-glucuronidase (P<0.001) and increased activities of β-galactosidase and β-glucosidase. Bile acids concentration was significantly decreased (P<0.01) except for the combination of the prebiotic with Horse chestnut. The prebiotic alone decreased the lipid parameters (P<0.001) and enhanced production of short chain fatty acids. Application of prebiotic and bioactive natural substances significantly reduced number of coliforms (P<0.05). Prebiotic alone significantly increased the count of lactobacilli (P<0.05). These results show that prebiotics have a protective effect and may be the useful for colon cancer prevention and treatment.
EN
Diosgenin is a steroidal sapogenin present in fenugreek and Dioscorea spp. as glycosides (saponins). Diosgenin has already been reported to inhibit osteoclastogenesis and to stimulate osteogenic activity of osteoblastic cells in vitro, and to exert some antiosteoporotic effects in rats in vivo. The aim of the present study was to investigate the effects of diosgenin administration on the skeletal system of rats with normal estrogen level and with estrogen deficiency induced by bilateral ovariectomy. The experiments were carried out on 3-month-old non-ovariectomized and ovariectomized Wistar rats, divided into control rats and rats receiving diosgenin (50 mg/kg p.o. daily) for 4 weeks. Serum bone turnover markers, bone mass and mineralization, histomorphometric parameters and mechanical properties were studied. Diosgenin improved some investigated parameters in both non-ovariectomized and ovariectomized rats, in which estrogen deficiency induced osteoporotic changes. Diosgenin increased compact bone formation and probably inhibited cancellous bone resorption, which led to improvement of mechanical properties of compact and cancellous bone. In conclusion, this in vivo study demonstrated that diosgenin may be one of sparse compounds increasing bone formation.
EN
Xanthan gum-based hydrogel formulation FXG3 was prepared by a free radical polymerization technique. To assess safety of FXG3 hydrogel for potential application as new drug delivery system, a single oral dose toxicity study was conducted according to OECD guidelines. Female adult rats of Wistar strain were divided into group A and group B. Group A served as the control and was given 1mL/100 g body weight 0.9% saline. Group B received a dose of 5g/kg body weight of FXG3 hydrogel. Rats were observed continuously for 14 days for clinical signs, and prior to terminal sacrifice, blood samples were taken to assess for haematology and biochemical parameters. Selected organs (heart, liver, lung, kidneys, spleen, and stomach) were removed and examined macroscopically, washed, sliced and stained with haematoxylin-eosin for histopathological investigation. No mortality or any signs of acute toxicity was observed during the observation period. No macroscopic alteration was found in the selected organs. Histopathological examination did not show any pathological changes. Thus, the maximal tolerated dose of FXG3 was calculated to be higher than 5g/kg body weight. It can be concluded that FXG3, a xanthan gum-based hydrogel formulation, was non-toxic after acute oral administration at 5g/kg body weight, and thus may be a promising candidate in controlled drug delivery system.
15
Content available remote Type IV resistant starch increases cecum short chain fatty acids level in rats
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EN
Resistant starches are type of dietary fibers. However, their physiological effects depend on the way they resist digestion in the gastrointestinal tract. The objective of this study was to examine the hypothesis that new type of RS4 preparations, of in vitro digestibility of about 50%, obtained by cross-linking and acetylation, acts as a prebiotic by increasing short chain fatty acids content in cecum digesta. The rats were fed with diet containing pregelatinized, cross-linked and acetylated starches as a main carbohydrate source. Pregelatinized, but not chemically modified, potato starch was used in the composition of the control diet. After two weeks of experiment the increase of short chain fatty acids contents in ceceum digesta was observed. The intake of starch A, cross-linked only with adipic acid, resulted in increase of about 40% of short chain fatty acids content, whereas starch PA cross-linked with sodium trimetaphosphate and adipic acid of about 50%. The utmost twofold increase was observed in the case of the production of propionic acid. In contrast, the content of butyric acid increased (12%) only as an effect of consumption of starch PA and even decreased (about 30%) in case of starch A. Both RS4 starches caused an increase of the production of acetic acid by more than 40%. No changes in serum biochemistry, liver cholesterol and organ weights of rats were stated.
EN
Objectives: This paper presents toxic effects of 2-MN in laboratory animals under conditions of 4-week inhalation exposure to 2-methylnaphthalene (2-MN) vapors. Materials and Methods: Male Wistar rats were exposed to 2-MN vapors at a nominal concentration of 0, 2, 10 or 50 mg/m³ in dynamic inhalation chambers for 4 weeks (6 h/day, 5 days/week). After 4 weeks of inhalation exposure the animals were necropsied. Blood samples were collected and selected organs were weighted and prepared for histological examinations. Results: The effects of the increased levels of exposure to 2-MN experienced by the experimental rats were as follows: a) increasing γ-glutamylotransferase activity, b) stimulation of the hematopoietic system, c) lower cholesterol concentrations, d) higher number of goblet cells in lobar bronchi, e) hyperplasia of hepatic bile ducts. Conclusion: Four-week exposure of the animals to 2-MN at 2 mg/m³ proved to be the no-observed-adverse-effect-level (NOAEL), while 10 mg/m³ appeared to represent the lowest-observed-adverseeffect- level (LOAEL).
EN
Relation between depression and myocardial infarction is known, but the mechanism that explains depression occurrence after myocardial infarction (AMI) is still unclear. The objective of this study was to review the literature to better understand the pathogenesis of post-myocardial infarction depression. Using a strategy similar to systematic review, we found experimental and clinical evidences. The post-myocardial infarction depression (PMID) has multiple causes such as psychological, biological dysfunctions or a combination of both. The inflammation of central nervous system and neurons destruction in specific regions of the brain resulted of AMI could be responsible to PMID, and it seems to be the main mechanism.
EN
Objectives: Exposure to various stressors is known to result in sensitization to psychostimulants, a state related to the psychostimulant dependence and addiction. It has been shown in some studies that the rise in corticosterone (CORT) concentration is indispensable for both the induction and the expression of behavioral sensitization. Therefore, it might be suspected that behavioral hyposensitivity to amphetamine (AMPH) is somehow related to a reduced CORT response to the psychostimulant subsequent to the chlorphenvinphos (CVP) intoxication. Materials and Methods: The male adult Wistar rats received single i.p. injections of CVP at the doses 0.5, 1.0 or 3.0 mg/kg b.w., or pure corn oil. CORT concentration was determined in samples of blood drawn from the tail vein before and then 30, 60, 180 min and 24 h after injection. The other rats were divided into two groups and tested, three weeks after the CVP injection for the effect of AMPH (0.5 mg/kg b.w. i.p.) on the serum CORT concentration. In addition, behavioral sensitivity to AMPH was assessed by measuring locomotor activity of the animals in an open-field. Results: 1) The stressor property of CVP was confirmed. The injection resulted in up to tenfold increase in the serum CORT concentration. The magnitude and duration of this response were dose-related. 2) Three weeks after the CVP exposure, the CORT response to AMPH was significantly increased. 3) The behavioral response to the psychostimulant, i.e. augmented locomotion, was significantly reduced compared to the control. Conclusions: The results confirm that CVP exposure causes behavioral hyposensitivity to AMPH. This effect, however, could not be ascribed to a diminished CORT response.
EN
A novel indolamine derivative, ADN-2013, has been proved to possess a preclinical activity profile appropriate for the treatment of behavioral and psychological symptoms of dementia. Its antidepressant and anxiolytic properties have been examined in rat and mice models. The receptor mechanisms underlying the antidepressant properties of ADN-2013 have also been elucidated. ADN-2013 significantly shortened the immobility time measured in the forced swim test in mice and rats, producing an effect that was abolished by the dopamine D1-receptor antagonist SCH 23390 in rats. Moreover, ADN-2013 evoked anxiolytic-like activity in both “conditional” and “unconditional” anxiety-like paradigms in mice and rats. From these results, it is likely that direct antagonism toward serotonin 5-HT6 receptors and an indirect effect of dopamine, acting mostly via D1-like receptors, may be involved in the antidepressant action of ADN-2013. However, the partial agonist activity of ADN-2013 toward D2 receptors, observed in in vitro studies, might also contribute to this effect.
EN
Objectives The aim of this study is the evaluation of the influence of repeated (5 times for 15 min) exposure to electromagnetic field (EMF) of 1800 MHz frequency on tissue lipid peroxidation (LPO) both in normal and inflammatory state, combined with analgesic treatment. Material and Methods The concentration of malondialdehyde (MDA) as the end-product of the lipid peroxidation (LPO) was estimated in blood, liver, kidneys, and brain of Wistar rats, both healthy and those with complete Freund’s adjuvant (CFA)-induced persistent paw inflammation. Results The slightly elevated levels of the MDA in blood, kidney, and brain were observed among healthy rats in electromagnetic field (EMF)-exposed groups, treated with tramadol (TRAM/EMF and exposed to the EMF). The malondialdehyde remained at the same level in the liver in all investigated groups: the control group (CON), the exposed group (EMF), treated with tramadol (TRAM) as well as exposed to and treated with tramadol (TRAM/EMF). In the group of animals treated with the complete Freund’s adjuvant (CFA) we also observed slightly increased values of the MDA in the case of the control group (CON) and the exposed groups (EMF and TRAM/EMF). The MDA values concerning kidneys remained at the same levels in the control, exposed, and not-exposed group treated with tramadol. Results for healthy rats and animals with inflammation did not differ significantly. Conclusions The electromagnetic field exposure (EMF), applied in the repeated manner together with opioid drug tramadol (TRAM), slightly enhanced lipid peroxidation level in brain, blood, and kidneys.
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