Olfaction enables most mammalian species to detect and discriminate vast numbers of chemical structures called odorants and pheromones. The perception of such chemical compounds is mediated via two major olfactory systems, the main olfactory system and the vomeronasal system, as well as minor systems, such as the septal organ and the Grueneberg ganglion. Distinct differences exist not only among species but also among individuals in terms of their olfactory sensitivity; however, little is known about the mechanisms that determine these differences. In research on the olfactory sensitivity of mammals, scientists thus depend in most cases on behavioral testing. In this article, we reviewed scientific studies performed on various mammalian species using different methodologies and target chemical substances. Human and non-human primates as well as rodents and dogs are the most frequently studied species. Olfactory threshold studies on other species do not exist with the exception of domestic pigs. Olfactory testing performed on seals, elephants, and bats focused more on discriminative abilities than on sensitivity. An overview of olfactory sensitivity studies as well as olfactory detection ability in most studied mammalian species is presented here, focusing on comparable olfactory detection thresholds. The basics of olfactory perception and olfactory sensitivity factors are also described., M. Wackermannová, L. Pinc, L. Jebavý., and Obsahuje bibliografii
There is a large body of evidence documenting the effects of long-chain polyunsaturated fatty acids with the first double bond at the third position from methyl-terminal (so called omega-3 fatty acids (FAs)) on different components of cardiovascular disease (CVD) risk. However, it may seem the more answers on the topic we learn, the more questions remain to be elucidated. There are three levels of evidence documenting the impact of fish omega-3 FAs on CVD risk. Epidemiological data have shown unequivocally the increased intake of fish is associated with lower CVD morbidity and mortality. Numerous experimental studies have shown (almost always) positive effects of omega-3 FAs on lipoprotein metabolism, coagulation and platelet function, endothelial function, arterial stiffness etc. Most importantly, there are a few prospective clinical endpoint trials (DART, JELIS, GISSI Prevenzione and GISSI-HF) that have examined the impact of omega-3 FAs supplementation on cardiovascular outcomes in different patient populations. Recent meta-analyses of these and other clinical studies have yielded somewhat conflicting results. In this review we will summarize current evidence of omega-3 FAs effects on cardiovascular risk focusing on new data from recent clinical trials as well as possible practical implications for clinical practice., M. Vrablík ... [et al.]., and Obsahuje seznam literatury
Omega-3 fatty acids (Ω3FA) are known to reduce hypertriglyceridemia- and inflammation-induced vascular wall diseases. However, mechanisms of their effects are not completely clear. We examined, whether 10-day Ω3FA diet can reduce bacterial lipopolysaccharide-induced changes in expression of gap junction protein connexin40 (Cx40) in the aorta of hereditary hypertriglyceridemic (hHTG) rats. After administration of a single dose of lipopolysaccharide (LPS, 1 mg/kg, i.p.) to adult hHTG rats, animals were fed with Ω3FA diet (30 mg/kg/day) for 10 days. LPS decreased Cx40 expression that was associated with reduced acetylcholine-induced relaxation of aorta. Ω3FA administration to LPS rats had partial anti-inflammatory effects, associated with increased Cx40 expression and improved endothelium dependent relaxation of the aorta. Our results suggest that 10-day Ω3FA diet could protect endothelium-dependent relaxation of the aorta of hHTG rats against LPS-induced damage through the modulation of endothelial Cx40 expression, K. Frimmel, R. Sotníková, J. Navarová, I. Bernátová, J. Križák, Z. Haviarová, B. Kura, J. Slezák, Ľ. Okruhlicová., and Obsahuje bibliografii
The effect of three therapeutically used drugs and five polyphenolic compounds on the mechanism of oxidative burst was compared in whole blood and isolated neutrophils at cellular and molecular level. In 10 μM concentration, the compounds investigated decreased the oxidative burst of whole blood in the rank order of potency: N-feruloylserotonin (N-f-5HT) > curcumin (CUR) > quercetin (QUER) > arbutin (ARB) > resveratrol (RES) > dithiaden (DIT) > carvedilol (CARV) > brompheniramine (BPA). The ratio between the percentage inhibition of extracellular versus intracellular chemiluminescence (CL) followed the rank order QUER > N-f-5HT > RES > CUR > DIT and is indicative of the positive effect of the compounds tested against oxidative burst of neutrophils, demonstrating suppression of reactive oxygen species extracellularly with minimal alteration of intracellular reactive oxygen species (ROS). Activation of protein kinase C was significantly decreased by DIT, CUR, QUER and N-f-5HT. CARV, DIT, QUER and ARB reduced activated neutrophil myeloperoxidase release more significantly compared with the effect on superoxide anion generation. All compounds tested increased the activity of caspase-3 in cell-free system. It is suggested that other regulatory mechanisms than protein kinase C might participate in the inhibition of neutrophil activation with the compounds tested. Different mechanisms are concerned in controlling the assembly of NADPH oxidase and the regulatory role of calcium ions is suggested. Compounds decreasing the amount of extracellular ROS generation, yet affecting but minimally intracellular ROS generation, are promising for further investigation in vivo., R. Nosáľ, K. Drábiková, V. Jančinová, T. Mačičková, J. Pečivová, T. Perečko, J. Harmatha, J. Šmidrkal., and Obsahuje bibliografii
Ongoing interest in brain ischemia research has provided data showing that ischemia may be involved in the pathogenesis of Alzheimer disease. Brain ischemia in the rat produces a stereotyped pattern of selectiv e neuronal degeneration, which mimics early Alzheimer disease pathology. The objective of this study was to further develop an d characterize cardiac arrest model in rats, which provides practical way to analyze Alzheimer- type neurodegeneration. Rats were made ischemic by cardiac arrest. Blood-brain barrier (BBB) insufficiency, accumulation of different parts of amyloid precursor protein (APP) and platelets inside and outside BBB vessels were investigated in ischemic brain up to 1-year survival. Isch emic brain tissue demonstrated haphazard BBB changes. Toxic fr agments of APP deposits were associated with the BBB vessels. Moreover our study revealed platelet aggregates in- and outside BBB vessels. Toxic parts of APP and platelet aggregates correlated very well with BBB permeability. Progressive injury of the ischemic brain parenchyma may be caused not only by a degeneration of neurons destroyed during ischemia but also by chronic damage in BBB. Chronic ischemic BBB insufficiency with accumulation of toxic components of APP in the brain tissue perivascular space, may gradually over a lifetime, progress to brain atrophy and to full blown Alzheimer-type pathology., M. Jabłoński., and Obsahuje bibliografii a bibliografické odkazy
Mitral allografts are still used only exceptionally in the mitral or tricuspid position. The main indication remains infectious endocarditis of atrioventricular valves for its flexibility and low risk of infection. The aim of our study was to evaluate 1-year results of mitral allografts transplantation into the tricuspid position in a sheep model. Mitral allografts were processed, cryopreserved, a nd transplanted into the tricuspid position anatomically (Group I - 11 animals) or antianatomically (Group II - 8 animals). All survivors (4 from Group I, and 3 from Group II) were checked at 3, 6, and 12 months by echocardiography with the exception of one survivor from Group II (which was examinated only visually). Examination throughout follow-up included for mitral allograft regurgitation and annuli dilatation. At postmortem, the papillary muscles were healed and firmly anchored to the right ventricular wall in all subjects. Transventricular fixation of the papillary muscles with buttressed sutures was proven to be a stable, reproducible, and safe method for anchoring mitral allograft leaflets. There were no significant differences between the two implan tation methods. Annulus support of mitral allografts might be very useful in this type of operation and could prevent annular dilatation., A. Mokracek, J. Canadyova, Z. Simunkova, R. Fiala, M. Hmirak, M. Sulda, J. Burkert, J. Tintera, P. Kobylka, J. Spatenka., and Obsahuje bibliografii
Increased generation of reactive oxygen species results in the formation of fluorescent end-products of lipid peroxidation – lipofuscin-like pigments (LFP). LFP increased up to six-fold from the fetal value in the rat heart immediately after birth. In the experimental design of this study the fetuses were sampled 1 day before birth, and then the samples were collected on postnatal days 1, 4, 7, 10, 15, 30, and 60. Males and females were compared on day 30 and 60 when the difference between right and left ventricle was studied as well. Four LFP fluorophores were analyzed: F355/440, F310/470, F350/450, F315/450 (excitation/emission, nm). All fluorophores decreased on day 4 relative to day 1, subsequent transient increases ended in a significant decrease on day 60. However, the LFP levels on day 60 are still about threefold higher than those in fetuses. Differences between male and female hearts were observed on day 30. The corresponding male ventricles contained by one third higher concentration of LFP than the female counterparts. The increase in LFP concentration in male ventricles on day 30 was only transient, no difference between corresponding male and female ventricles was found on day 60. The most distinguished feature in the male heart was a sharp LFP decrease in the right ventricle on day 60., J. Wilhelm, I. Ošťádalová., and Obsahuje seznam literatury
Our present focus on the hypoxic immature heart is driven by clinical urgency: cyanotic congenital cardiac malformations remain the single largest cause of mortality from congenital defects and ischemic heart disease is no more the disease of the fifth and older decades but its origin as well as risk factors are present already during early ontogeny. Moreover, the number of adult patients operated for cyanotic congenital heart disease during infancy steadily increases. This group approaches the age of the rising risk of serious cardiovascular diseases, particularly ischemic heart disease. Experimental results have clearly shown that the immature heart is significantly more tolerant to oxygen deficiency than the adult myocardium. However, the mechanisms of this difference have not yet been satisfactorily clarified; they are likely the result of developmental changes in cardiac energy metabolism, including mitochondrial function. The high resistance of the newborn heart cannot be further increased by ischemic preconditioning or adaptation to chronic hypoxia; these protective mechanisms appear only with decreasing tolerance during development. Resistance of the adult myocardium to acute oxygen deprivation may be significantly influenced by perinatal hypoxia. These results suggest that the developmental approach offers new possibilities in the studies of pathogenesis, prevention and therapy of critical cardiovascular diseases., B. Ošťádal ... [et al.]., and Obsahuje seznam literatury
a1_The purpose of the present study was to compare the ontogenetic development of the activity of myocardial energy-supplying enzymes in two mammalian species, differing significantly in their level of maturation at birth. The animals were investigated during the late prenatal period and 2, 7, 14, 21, 25, 30, 63, 120 and 730 days after birth in the rat and 2, 21, 84 and 175 days in the guinea-pig. The following enzymes were assayed in the right and left ventricular myocardium: lactate dehydrogenase (LDH, lactate uptake and/or formation), triose phosphate dehydrogenase (TPDH, carbohydrate metabolism), glycerol phosphate dehydrogenase (GPDH, glycerol-P shuttle)), hexokinase (HK, glucose phosphorylation), malate dehydrogenase (MDH, tricarboxylic cycle), citrate synthase (CS, tricarboxylic cycle) and hydroxyacyl-CoA dehydrogenase (HOADH, fatty acid breakdown). The rat heart, highly immature at birth, exhibits three different developmental patterns of energy-supplying enzymes, identical in both ventricles: (i) two mitochondrial enzymes of aerobic metabolism (CS, HOADH) and GPDH have a relatively low activity at the end of prenatal life; thereafter their activity steadily increases, approaching the adult levels between the 3rd and 4th postnatal weeks. A significant decrease was observed between the 4th and 24th months. (ii) MDH and LDH: prenatal values were significantly higher as compared with the 2nd postnatal day; after this period the activities increased up to adulthood (4 months) and decreased during senescence. (iii) The activities of HK and TPDH are characterized by only moderate changes during development. HK differs from all other enzymes by the highest prenatal values, which exceed even adult values. In contradiction to the rat heart, the developmental differences in more mature guinea-pig heart were significantly less pronounced., a2_The only ontogenetic differences observed were the lower activities of enzymes connected with aerobic metabolism at the end of the prenatal period. Our results point to possible differences in the development of adaptive metabolic pathways in animals with different levels of maturation at birth., A. Bass, M. Stejskalová, A. Stieglerová, B. Ošťádal, M. Šamánek., and Obsahuje bibliografii
Our data indicate the significant intrinsic efficacy of GABABreceptors in rat brain cortex already at birth (PD1, PD2). Subsequently, baclofen- and SKF97541-stimulated G-protein activity, measured by agonist-stimulated, high-affinity [35S]GTPγS binding assay, was increased; the highest level of both baclofen and SKF97541-stimulated [35S]GTPγS binding was detected between PD10 and PD15. In older rats, baclofen- and SKF97541- stimulated [35S]GTPγS binding was continuously decreased so, that the level in adult, 90-days old animals, was not different from that in newborn animals. The potency of G-protein response to baclofen (characterized by EC50 values) was also high at birth but unchanged by further postnatal development. An individual variance among different agonists was observed in this respect as the potency of SKF97541 response was decreased between the birth and adulthood. Accordingly, the highest plasma membrane density of GABAB-R, determined by saturation binding assay with antagonist [3 H]CGP54626, was measured in 1-day old animals (2.27±0.08 pmol · mg-1). The further development was reflected in a decrease of [3 H]CGP54626 binding as the Bmax values of 1.38±0.05 and 0.93±0.04 pmol · mg-1 were determined in PM isolated from 13- and 90-days old rats, respectively., D. Kagan, ... [et al.]., and Obsahuje seznam literatury