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27962. Ontogenesis of melatonin receptors in anterior pituitary and pars tuberalis of golden hamsters
- Creator:
- Vaněček, J. and Kosař, E.
- Type:
- article, model:article, and TEXT
- Subject:
- melatonin receptor, anterior pituitary, pars tuberalis, ontogenesis, and golden hamster
- Language:
- English
- Description:
- The ontogenesis of melatonin receptors in the anterior pituitary and pars tuberalis of the Golden hamster was studied using [125l]iodomelatonin as a ligand. The affinity of the binding site to the ligand (K<j) was in the range 21 to 54 pM and it did not change significantly during development. The concentration of the [125lliodomelatonin binding sites in the anterior pituitary was highest in one-day-old hamsters (Bmax=14 fmol/mg protein) and thereafter gradually decreased. In adults it reached to about 6 % of the neonatal values. In contrast, the concentration of the binding sites in pars tuberalis did not change significantly during ontogenesis and it was in the range of 3 to 5 fmol/mg protein.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27963. Ontogenetic changes of lipofuscin-like pigments in the rat heart
- Creator:
- Wilhelm, J. and Ivana Ošťádalová
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, rat heart, ontogenetic development, lipofuscin-like pigments (LFP), reactive oxygen species (ROS), gender difference, right /left ventricle ratio, 14, and 612
- Language:
- English
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27964. Ontogenetic development of cardiac tolerance to oxygen deprivation - possible mechanisms
- Creator:
- Bohuslav Ošťádal, Ivana Ošťádalová, František Kolář, Zuzana Charvátová, and Ivan Netuka
- Type:
- article, články, model:article, and TEXT
- Subject:
- Patologie. Klinická medicína, kardiologie, hypoxie, ischemie, ontogeneze, cardiology, hypoxia, ischemia, ontogeny, odolnost srdce, ochrana srdce, cardiac tolerance, cardiac protection, 14, and 616
- Language:
- English
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27965. Ontogenetic development of energy-supplying enzymes in rat and guinea-pig heart
- Creator:
- Bass, A., Marie Stejskalová, Andrea Stieglerová, Bohuslav Ošťádal, and Milan Šamánek
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdce, energetický metabolismus, morčata, heart, energy metabolism, Guinea pigs, ontogenetic development, rat, 14, and 612
- Language:
- English
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27966. Ontogenetic development of GABAB-receptor signaling cascade in plasma membranes isolated from rat brain cortex: the number of GABAB-receptors is high already shortly after the birth
- Creator:
- Kagan, D., Dlouhá, K., Roubalová, L., and Svoboda, P.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, postnatal development, GABAB-receptor, G-protein coupling/ activation, baclofen, SKF97541, 14, and 612
- Language:
- English
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27967. Ontogenetic development of sensitivity of the cerebral cortex to an Antagonist of GABAA receptor bicuculline
- Creator:
- Pavel Mareš, Klára Bernášková, and Hana Kubová
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyziologie člověka, human physiology, Cerebral cortex, Rat, Postnatal development, Epileptic phenomena, Bicuculline, 14, and 612
- Language:
- English
- Description:
- Local application of four concentrations of bicuculline methiodide (a specific antagonist of GABAA receptors) was used to study a sensitivity of somatosensory cortex in four age groups of immature rats with implanted electrodes. Presence and latencies of two epileptic phenomena (focal discharges and seizures) were evaluated. Focal discharges exhibited moderate tendency to a decrease of sensitivity to bicuculline methiodide with maturation. Concentration-effect relation of incidence of focal discharges was observed only in 7- and 12-day-old but not in older animals. Results with incidence and latencies of seizures did not show relations to age or concentration of bicuculline. Neither of the epileptic phenomena can be used as a reliable index of cortical maturation., P. Mareš, K. Bernášková, H. Kubová., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
27968. Ontogenetic dietary shifts in the summer feeding intensity of brown trout in relation to fish condition
- Creator:
- Sánchez-Hernández, Javier and Cobo, Fernando
- Type:
- article, model:article, and TEXT
- Subject:
- Salmo trutta, feeding activity, condition factor, hepatosomatic index, and ontogeny
- Language:
- English
- Description:
- We examined condition factor, hepatosomatic index and stomach fullness in brown trout to study if feeding intensity can be related to fish condition. Trout were collected at three locations during the summer in temperate rivers (Galicia, NW Spain). Our findings suggest that the feeding intensity is inversely related with the fish condition because the stomach fullness decreases with fish age and size and the condition factor is the lowest in young-of-the-year (YOY). In general, no significant differences among age classes were found in the hepatosomatic index, except in one river (the River Lengüelle) in which YOY shows the highest value. The high feeding intensity of YOY during summer could be related with the increases in fish condition and survival in the later autumn and winter.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27969. Ontogenetic differences in cardiopulmonary adaptation to chronic hypoxia
- Creator:
- Ošťádal, B., Kolář, F., Pelouch, V., and Widimský, J.
- Type:
- article, model:article, and TEXT
- Subject:
- ontogeny, rat, adaptation, chronic hypoxia, right ventricle, and pulmonary hypertension
- Language:
- English
- Description:
- Cardiopulmonary adaptation to chronic hypoxia was compared in rats exposed to simulated high altitude (barochamber, 8 h per day, 5 days a week, stepwise up to 7000 m, a total of 24 exposures) either from the 4th day or the 12th week of postnatal life. Pulmonary hypertension and right ventricular (RV) enlargement were comparable in both age groups. Whereas in young hypoxic animals the individual values of RV weight increased linearly with a rise of RV pressure (r=0.72), no significant correlation was found in adult rats. Chronic hypoxia increased the concentration of cardiac collagenous proteins; this effect was more pronounced in adult animals. On the other hand, the collagen l/lll ratio was markedly lower in young rats suggesting increased synthesis of collagen III in this age group. A protective effect of adaptation, i.e. increased cardiac resistance to acute hypoxic injury, was similar in both age groups and persisted even 4 months after removal of animals from the hypoxic atmosphere.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
27970. Ontogenetic profile of ecto-ATPase activity in rat hippocampal and caudate nucleus synaptic plasma membrane fractions
- Creator:
- Banjac, A., Nedeljković, N., Horvat, A., Dušan Kanazir, and Nikezić, G.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, stárnutí, mozek, aging, brain, ecto-ATPase, extracellular purines, development, 14, and 612
- Language:
- English
- Description:
- An ontogenetic study of ecto-ATPase activity and the content of enzyme proteins was assessed in the caudate nucleus and hippocampal synaptic plasma membranes isolated from rats at various ages (15, 30, 90, 180 and 365 days). The ontogenetic profile revealed that the enzyme activities in both brain areas were the highest on day 30 and 365, while the ecto-ATPase protein abundance was the highest on day 15 after birth. Possible explanation for obtained ontogenetic profile and the discrepancy between activity and abundance may reside in the fact that ecto-ATPase during development could exert additional roles other than those related to metabolism of ATP. It is likely that ecto-ATPase, regulating the concentration of ATP and adenosine in synaptic cleft, has important role in the processes of brain development and aging., A. Banjac, N. Nedeljković, A. Horvat, D. Kanazir, G. Nizekić., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public