Monophasic action potential (MAP) can be recorded from the heart surface by optical method based on fluorescence measurement. The motion of isolated heart during experiment caused additional noise in recorded signal. The motion artifact can be eliminated by ratiometric fluorescence emission measurements. This study is based on experiments in which optical MAP measurement is done by single-wavelength and dualwavelength measurement of fluorescence emission. Both recording setups are presented and their advantages and disadvantages are discussed. MAPs recorded by both methods from isolated rabbit hearts perfused according to Langendorff are presented. Simultaneous electrograms (EG) and MAPs recording are analyzed and measurement of velocity of impulse conduction through heart tissue is presented., J. Kolářová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Acute lung injury in the preterm newborns can originate from prematurity of the lung and insufficient synthesis of pulmonary surfactant. This situation is known as respiratory distress syndrome (RDS). In the term neonates, the respiratory insufficiency is related to a secondary inactivation of the pulmonary surfactant, for instance, by action of endotoxins in bacterial pneumonia or by effects of aspirated meconium. The use of experimental models of the mentioned situations provides new information on the pathophy siology of these disorders and offers unique possibility to test novel therapeutic approaches in the conditions which are very similar to the clinical syndromes. Herewith we review the advantages and limitations of the use of experimental models of RDS and meconium aspiration syndrome (MAS) and their value for clinics., D. Mokra, A. Calkovska., and Obsahuje bibliografii
The first experimental model of atherosclerosis (in rabbits) is more than hundred years old. Several animal species have bee n used to produce hyperlipoproteine mia and possible atherosclerosis. The gene manipulation produced the most used models recently. This review acknowledges the extensive study of atherosclerotic changes in experimental models of hyperlipoprotein emia and at herosclerosis to come to light thus far and the purpose here is not only to summariz e the published data but also to try to add some details of our experience in using these models. In addition to rabbit (the old but also improved model by reno-vascular hy pertension) dog, birds, pig, hamster, mice, rat and non-human primate’s animal models are described. The gene manipulation produced the most used models two decades ago. Germline genetically engineered (without apoE or LDL receptor genes) animals have beco me the most used models producing atherosclerotic changes in the aorta. Recent new models also producing atherosclerotic changes but without germline genetic manipulation are also described., R. Poledne, L. Jurčíková-Novotná., and Obsahuje bibliografii
Sudden cardiac death defined as natural death from cardiac causes occurring within one hour of the onset of acute symptoms is one of the most significant non-injury causes of death in the adult population of industrialised countries. The understanding of the mechanisms leading to sudden cardiac death is so far limited. Recently, a number of experimental animal models with high incidence of sudden cardiac death were developed and are intensively studied to get new insights into the sudden cardiac death mechanisms. In this review the animal models of sudden cardiac death are summarized and their principal properties shortly described., M. Štengl., and Obsahuje bibliografii a bibliografické odkazy
a1_In the present study, the effect of the medial septal (MS) lesions on exploratory activity in the open field and the spatial and object recognition memory has been investigated. This experiment compares three types of MS lesions: electrolytic lesions that destroy cells and fibers of passage, neurotoxic -ibotenic acid lesions that spare fibers of passage but predominantly affect the septal noncholinergic neurons, and immunotoxin - 192 IgG -saporin infusions that only eliminate cholinergic neurons. The main results are: the MS electrolytic lesioned rats were impaired in habituat ing to the environment in the repeated spatial environment, but rats with immuno - or neurotoxic lesions of the MS did not differ from control ones; the MS electrolytic and ibotenic acid lesioned rats showed an increase in their exploratory activity to the objects and were impaired in habituating to the objects in the repeated spatial environment; rats with immunolesions of the MS did not differ from control rats; electrolytic lesions of the MS disrupt spatial recognition memory; rats with immuno - or neurotoxic lesions of the MS were normal in detecting spatial novelty; all of the MS - lesioned and control rats clearly reacted to the object novelty by exploring the new object more than familiar ones. Results observed across lesion techniques indicate that: (i) the deficits after nonselective damage of MS are limited to a subset of cognitive processes dependent on the hippocampus, (ii) MS is substantial for spatial, but not for object recognition memory - the object recognition memory can be supported outside the septohippocampal system; (iii) the selective loss of septohippocampal cholinergic or noncholinergic projections does not disrupt the function of the hippocampus to a sufficient extent to impair spatial recognition memory;, a2_(iv) there is dissociation between the two major components (cholinergic and noncholinergic) of the septohippocampal pathway in exploratory behavior assessed in the open field - the memory exhibited by decrements in exploration of repeated object presentations is affected by either electr olytic or ibotenic lesions, but not saporin., M. G. Dashniani, M. A. Burjanadze, T. L. Naneishvili, N. C. Chkhikvishvili, G. V. Beselia, L. B. Kruashvili, N. O. Pochkhidze, M. R. Chighladze., and Obsahuje bibliografii
It is known that psychostimulants including methamphetamine (MA) have neurotoxic effect, especially, if they are targeting CNS during its critical periods of development. The present study was aimed on evaluation of cognitive changes following scheduled prenatal MA exposure in combination with long-term exposure in adulthood of male rats. Two periods of gestation were targeted: 1st half - the embryonic day (ED) 1-11 and 2nd half - ED 12-22. Rat mothers received subcutaneously a daily injection of MA (5 mg/kg) or saline (SAL, 1 ml/kg) throughout scheduled periods. Male offspring were tested for cognitive changes in the Morris Water Maze (MWM) in adulthood. Each day of the experiment animals received an injection of MA (1 mg/kg) or SAL (1 ml/kg) during 12 days. Our results demonstrated that in the group of animals exposed to the drug during ED 1-11, neither prenatal MA exposure, nor adult MA treatment changed the performance in the MWM test. Only the velocity was increased in group with long-term MA treatment (SAL/MA and MA/MA). In the group of animals exposed to the drug during ED 12-22, rats exposed to MA prenatally and also in adulthood (MA/MA) swam faster but learned the position of the platform slower in the Place Navigation Test than animals exposed to SAL in adulthood (MA/SAL). In the Probe Test, MA/SAL had decreased velocity and swam shorter distance than MA/MA or SAL/SAL rats suggesting increased floating of these animals. In the Memory Retention Test, SAL/MA rats swam shorter distance than SAL/SAL or MA/MA animals suggesting changes in used strategies in memory recall. As conclusion, our results suggest differences in the effect of combination of prenatal and adult exposure to MA. These effects further depend on the stage of CNS development and schedule of MA exposure affecting intrauterine development in male rats., I. Hrebíčková, M. Malinová-Ševčíková, E. Macúchová, K. Nohejlová, R. Šlamberová., and Obsahuje bibliografii
Aquaporins (AQPs) are water channel proteins responsible for water homeostasis and important for proper functioning of all body systems, including reproductive structures. This study was designed to determine their localization and quantitative changes in the pig ovary during different stages of the estrous cycle and early pregnancy. The expression of AQP 1, 5 and 9 proteins was determined by immunocytochemistry and Western blot analyses. AQP1 was found in the plasma membranes of capillary endothelium, AQP5 - in the plasma membranes of granulosa cells of developing follicles and flattened follicle cells of the primordial follicles, and AQP9 - in granulosa cells of the developing follicles. In the cyclic pigs, the expression of AQP1 and 5 proteins was the highest on Days 18-20, but did not change significantly between Days 2-4, 10-12 and 14-16 of the cycle. In pregnant pigs (Days 14-16 and 30-32), the expression of AQP1 and 5 did not change and was similar to that observed during Days 10-12 and 14-16. In turn, AQP9 expression did not change between all studied periods. In conclusion, studied AQP are localized in different cells populations, the endothelial and granulosa cells, and AQP1 and 5 seem to be crucial for follicular development in pigs., A. Skowronska, P. Mlotkowska, M. Eliszewski, S. Nielsen, M. T. Skowronski., and Obsahuje bibliografii
Estrogen replacement therapy could play a role in the reduction of injury associated with cerebral ischemia in vivo, which could be, at least partially, a consequence of estrogen influence of glutamate buffering by astrocytes during hypoxia/ischemia. Estrogen exerts biological effects through interaction with its two receptors: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which are both expressed in astrocytes. This study explored effects of hypoxia and glucose deprivation (HGD), alone or followed by 1 h recovery, on ERα and ERβ expression in primary rat astrocyte cultures following 1 h exposure to: a) 5 % CO2 in air (control group-CG); b) 2 % O2/5 % CO2 in N2 with glucose deprivation (HGD group-HGDG); or c) the HGDG protocol followed by 1 h CG protocol (recovery group-RG). ER α mRNA expression decreased in HGDG. At the protein level, full-length ER α (67 kDa) and three ER α -immunoreactive protein bands (63, 60 and 52 kDa) were detected. A significant decrease in the 52 kDa band was seen in HGDG, wh ile a significant decrease in expression of the full length ERα was seen in the RG. ERβ mRNA and protein expression (a 54 kDa single band) did not change. The observed decrease in ER α protein may limit estrogen-mediated signalling in astrocytes during hypoxia and recovery., M. D. Al-Bader, S. A. Malatiali, Z. B. Redzic., and Obsahuje bibliografii a bibliografické odkazy
Many stress conditions are ac companied by skeletal muscle dysfunction and regeneration, which is essentially a recapitulation of the embryonic development. However, regeneration usually occurs under conditions of hypo thalamus-pituitary -adrenal gland axis activation and therefore incr eased glucocorticoid (GC) levels. Glucocorticoid receptor (GR), the main determinant of cellular responsiveness to GCs, exists in two isoforms (GRα and GRβ ) in humans. While the role of GR α is well characterized, GRβ remains an elusive player in GC si gnalling. To elucidate basic characteristics of GC signalling in the regenerating human skeletal muscle we assessed GRα and GCβ expression pattern in cultured human myoblasts and myotubes and their response to 24-hour dexamethasone (DEX) treatment. There was no difference in GRα mRNA and protein expression or DEX-mediated GRα down-regulation in myoblasts and myotubes. GRβ mRNA level was very low in myoblasts and remained unaffected by differentiation and/or DEX. GRβ protein could not be detected. These results indicate that response to GCs is established very early during human skeletal muscle regeneration and that it remains practically unchanged before innervation is established. Very low GRβ mRNA expression and inability to detect GRβ protein suggests that GRβ is not a major player in the early stages of human skeletal muscle regeneration., D. Filipović ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy