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Pathogenesis of hypercholesterolemia in Prague hereditary hypercholesterolemic (PHHC) rat
Rybáková, Kateřina ; Vlachová, Miluše (advisor) ; Poledne, Rudolf (referee)
Hypercholesterolemia represents a major risk factor of cardiovascular disease. A number of experimental models is used for study of hypercholesterolemia pathogenesis and therapy. This thesis concentrates on characterization of one of these models. Prague hereditary hypercholesterolemic (PHHC) rat is such a suitable model for study of hypercholesterolemia. Although the majority of plasma cholesterol is transported by high density lipoprotein in PHHC rat fed standard diet, PHHC rat fed cholesterol diet develops hypercholesterolemia comparable to that of humans. The advantage of this model is that hypercholesterolemia develops without the need for addition of bile acids or other hepatotoxic substances to the diet. The hypercholesterolemia of PHHC rat is caused by slowed down catabolism of cholesterol-rich very low density lipoprotein (VLDL). These cholesterol-rich particles are synthesized in the liver. We found out that PHHC rat fed 1% cholesterol diet accumulates cholesteryl esters (CE) in the liver and also in the VLDL. Acyl-CoA:cholesterol acyltransferase (ACAT) and microsomal triglyceride transfer protein (MTP) may participate in the increased incorporation CE into VLDL. We found out no difference in ACAT and MTP activities in the liver between PHHC rats and control animals. Neither ACAT activity...
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Echocardiographic assessment of left ventricular systolic function in rats adapted to hypoxia and exercise training
Hrdlička, Jaroslav ; Papoušek, František (advisor) ; Vybíral, Stanislav (referee)
- 4 - Abstract Adaptation to hypoxia or exercise training has cardioprotective effects against acute ischemic injury, but can potentially negatively influence heart function. Possible negative changes depend on the degree of hypoxia and exercise training intensity. It is therefore necessary to evaluate the effects of the specific adaptation protocols used. The ideal technique is echocardiography, which enables non-invasive, repeated and long-term measurements of the same individual allowing to study the development of changes in the course of adaptation. The aim of this study was to determine the effects of selected protocols of adaptation to intermittent hypobaric hypoxia (corresponding to the altitude of 4,000 to 8,000 meters above sea level, for 15 weeks in total) and exercise training (running speed 30 m.min-1 for 60 min a day, 4 weeks in total) on the left ventricle geometry and systolic function in rats. We assessed basic echocardiographic parameters of the ventricle geometry and function such as fractional shortening, ejection fraction, stroke volume, cardiac output etc. The adaptation of rats to intermittent hypobaric hypoxia lead neither to the impairment of systolic function nor to the development of left ventricle hypertrophy compared to controls; signs of moderate hypertrophy were observed only...
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The influence of status epilepticus (SE) in postnatal development early phase on laboratory rat psychomotor development
Boťchová, Lenka ; Kubová, Hana (advisor) ; Mareš, Pavel (referee)
Bibliografická identifikace v angličtině Author's first name and surname: Lenka Boťchová, BA Title of the master thesis: Does status epilepticus during early postnatal period influence laboratory rat psychomotor development? Department: Department of Rehabilitation and Exercise Medicine Supervisor: doc. PharmDr. H. Kubová, DrSc. The year of presentation: 2013 Abstract: The purpose of this study is to evaluate the influence of status epilepticus (SE) in postnatal development early phase on laboratory rat psychomotor development. Experimentally caused (SE) is the most common mode of epileptogenesis, which is the process leading to the epilepsy creation, and typical comorbidities. The influence of the early SE was studied when using lithium/pilocarpine model of SE induced on 12 days old rat cubs, which were repeatedly exposed to the "open field" test until 32nd day of their lives that means until the puberty beginning. The evaluation is focused on cognition and overall locomotion changes and anxiety demonstrations. The results show that in short periods after SE (up to 1 month) the cognitive functions regarding the habituation disorder are not worsened. However, hyperactivity short-term disposition and worse adaptability to experimental conditions due to animal anxiety increase were detected. Motor skills of...
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Olfactory bulbectomy in laboratory rat as an animal model of depression
Entlerová, Marie ; Stuchlík, Aleš (advisor) ; Telenský, Petr (referee)
Removal of olfactory bulbs (olfactory bulbectomy; OBX) belongs amongst most interesting experimental phenomenons, which stimulated interesting hypotheses about the role of this structure in the CNS functions. It outreaches also to the preclinical research as an the animal model of depression-like behavior (usually pursued in the laboratory rats). Significance and all sequelae of olfactory bulbectomy probably cannot be covered in their extents by this thesis, therefore, I will first focus on short neuroanatomical description of connections between the olfactory bulbs and the limbic system, and short description of the OBX surgery will follow. Subsequently, I will discuss structural, molecular and neurochemical changes elicited by OBX. Next part of this work will be dedicated to OBX in relation to behavior; first I will present behavioral changes elicited by OBX with focus on learning and memory (and other cognitive functions) and then I would brieflysummarize the putative (for example endocrine, imunne) changes, witch can will be cause followin OBX. In conclusions, I will discuss usage of OBX as an animal model of depression.
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Applications of multiple reference frames environments in behavioral research
Telenský, Petr ; Bureš, Jan (advisor) ; Němec, Pavel (referee) ; Otáhal, Jakub (referee)
This work has been motivated by the desire to enhance our knowledge about specific cognitive requirements of navigation in multiple reference frames environments and to understand the roles of the hippocampus and posterior parietal cortex in this behavior. The main conclusions of this thesis are: (a) We have developed a novel behavioral test called the Enemy Avoidance Task. The initial set of experiments has shown that laboratory rats are able to plan their movement with respect to a to-be-avoided moving object. Behavioral performance in the task may be quantitatively evaluated. (b) The aforementioned ability is crucially dependent on the functional integrity of the dorsal hippocampus. To the contrary, functional inactivation of the dorsal hippocampi by local infusion of tetrodotoxin did not cause any impairment in the ability of the animal to estimate its distance from a non-moving object. The finding suggests a specific role of the hippocampus in dynamic cognitive processes required for flexible navigation strategies such as continuous updating of information about the position of a moving stimulus. These results are at odds with the two major theories of hippocampal function (Cognitive map theory and Declarative memory theory) and therefore suggest that revision of the theories is necessary. (c)...
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The influence of corticosterone and corticoliberin on damage of the hippocampus and their relation to cognition
Řezáčová, Lenka ; Mareš, Pavel (advisor) ; Mejsnar, Jiří (referee) ; Šusta, Marek (referee)
Dissertation "The influence of corticosterone and corticoliberin on damage of the hippocampus and their relation to cognition" deals with the cognitive, behavioral and histological changes in experimental rat strain long-evans that closer describe the consequences of long-term continuous application of corticoliberin and/or corticosterone. Testing of the behavioral changes was divided into two phases. The first one - within three or fourweeks respectively administration of these hormones, therefore until their early effects - and the second phase - after four weeks of completion of the first phase at the time of the possible late effects. In the twelfth week the experimental animals were killed and in the group which had exogenously elevated corticosterone, the morphological changes in the hippocampus were monitored and measured. In all experimental groups alteration of behavior was observed. Histological and morphological changes in the brain we have found. Layout of experiments in two testing phases allowed differentiation of the early changes and the late and persistent changes. The arrangement of experiments allowed the choice of tests to compare not only individual effects of both hormones (corticoliberin and corticosterone) but also their coactioning and biological responses to them. Using a wider...
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Development of motor behaviour in the laboratory rat
Vítová, Šárka ; Mareš, Pavel (advisor) ; Bitnar, Petr (referee)
Rats are born at an early stage of neuro-ontogeny, comparable to the foetal stage of the human ontogenesis. Gradual maturation of the nervous system manifests in a changing motor behaviour. Here we review the chronology of motor development in the rat, including ontogeny of sensorimotor reactions, postural control, ground locomotion and swimming. The aim of the thesis is also to take inventory of methods for assesing the motor development in rats. Important intrinsic and extrinsic factors in the ontogeny of motor behaviour are discussed. Powered by TCPDF (www.tcpdf.org)
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The pharmacological influencing of motor skills in juvenile laboratory rats
Stehlíková, Mariana ; Bitnar, Petr (referee) ; Mareš, Pavel (advisor)
Ganaxolone is a new potencional antiepileptic drug, synthetic analog of allopregnanolone which is a metabolite of progesterone. Preclinical and clinical studies point out its anticonvulsive effect in the treatment of both partial and generalized seizures including refractory epilepsy. The aim of our research was to investigate changes in the motor performance of the immature rats after administration of ganaxolone. We also focused on the relation between motoric impairment and the age of the rats which correlates with the age of children. 90 immature rats of age 12, 18 and 25 days were tested. Rats were divided in three groups injected with doses of 20 mgGNX/kg or 40 mgGNX/kg and the control group. The tests for assessing motor performance were chosen with respect to the maturation of sensorimotor reflexes from the following batery of tests: righting test, bar holding test, wire mesh test, negative geotaxis test and open field test. There were no significant differences before and after injection of the drug and in comparison with the control group not even in comparison of classes of age. We have demonstrated that the dose of ganaxolone effective against epileptic seizures does not markedly affect the motoric performance of the immature rats. Powered by TCPDF (www.tcpdf.org)
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Effect of tapeworm (Hymenolepis diminuta) on bioaccumulation of zinc in the host (Rattus norvegicus)
Sloup, Vladislav ; Jankovská, Ivana (advisor)
This research investigates the ability of rat tapeworm (Hymenolepis diminuta) to accumulate zinc in tissue and the influence of its intake and excretion by its host (laboratory rat). The host was fed by food with zinc in two forms: 1) a mixture of standard food ST1 with hyperaccumulator plant Arabidopsis halleri, 2) ST1 mixture with zinc lactate, which is ordinarily used as a feed supplement for increasing zinc content and it is often included in human diet supplements. Rat control group fed by ST1 only was included in the experiment for verification of the difference. Rats were divided to six groups (OO, OT, RT, RO, MO a MT). Three rat groups were infected by rat tapeworm (OT, RT, MT) and three rat groups were not infected (OO, RO, MO). The control groups OO and OT were fed by ST1 only. RO and RT groups were fed by ST1 with admixture of Arabidopsis halleri and groups MO and MT were fed by ST1 with zinc lactate. Urine and excrements of the rats were collected twice a week during the experiment and their amounts were measured every day. The rats were weighted every week. At the end of the balance phase of the experiment rats were euthanized and seven selected tissues were removed (liver, kidney, spleen, small intestine, testis, muscle and bone). Rat tapeworm was removed from the infected rats. Blood was drawn from the rats. The results show that rat groups infected by the rat tapeworm had lower concentration of zinc in almost all analyzed tissues except for spleen, where the concentration of zinc was the same as in groups without the rat tapeworm. Based on the results the rat tapeworm also has an influence on the excretion of feces and urine.
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Interaction between tapeworm infection and heavy metals accumulation in the host
Magdálek, Jan ; Jankovská, Ivana (advisor) ; Ivana, Ivana (referee)
Heavy metals in living organisms occur in trace amounts. While zinc is an essential element wich is indispensable for many physiological processes, cadmium in body acts
as atissue toxin, that can cause oxidative stress and contribute to cancer development. Recent studies suggest that some species of tapeworms (Cestoda) and Acantocephala are able
to absorb in their tissue higher quantity of heavy metals in comparsion with their hosts. Moreover it was observed that In connection with the increased accumulation of heavy metals in the tissue of tapeworm was decreased amounts of these metals in the organs of the host. The aim of this thesis was to investigate whether the rat tapevorm (Hymenolepis diminuta) causes a decrease in the concentration of Cd and Zn in the organs of rats. A total of 24 Wistar rats (Rattus norvegicus) were divided into 4 groups (n=6). Groups PT and 0P take increased doses of kadmium (3,0 mg/week) and zinc (235,7 mg/week) for six weeks. This increased intake was achieved by adding Arabidopis halleri to feed. After six weeks rats were killed and concentrations in their tissues (bone, muscle, testes, spleen, intestine, liver kidney) were analyzed. Subsequent statistical tests confirmed lower levels of Cd and Zn in some organs
of rats infected with tapeworm compared to rats without infection. For example
in kidney, liver ant intestine of infected rats was detected 2,9; 2,5 and 1,8 times lower concentrations of cadmium and zinc in comparsion with uninfected rats. Tapeworm absorbed 1695 time higher amount of kadmium compared to the host muscle. The zinc content was lower in all organs (except spleen and testes) of infected rats in comparsion to uninfected.
In kidney, liver and intestine of infected rats was 1,2; 1,25 and 1,4 times lower average concentration of zinc in comparsion with uninfected rats. The tape worm absorb higher concentration of zinc compared to all organs of the host.
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