1 - 9 of 9
Number of results to display per page
Search Results
2. Induction of cell-cycle inhibitor p21 in rat ventricular myocytes during early postnatal transition from hyperplasia to hypertrophy
- Creator:
- Horký, M., Kuchtíčková, Š., Vojtěšek, B., and Kolář, F.
- Type:
- article, model:article, and TEXT
- Subject:
- ventricular myocyte, cell cycle, proliferation, and postnatal development
- Language:
- English
- Description:
- To examine a possible involvement of p21 protein, an inhibitor of cyclin-dependent kinases (CDKs), in the transition from hyperplastic to hypertrophic growth of rat ventricular myocytes during the first postnatal week, we analysed day-by-day changes in the number of p21 positive cells using specific antibodies against this protein. Paraffin-embedded sections of the left ventricular myocardium were examined by means of immunoperoxidase technique and hematoxylin-eosin counterstaining. While during the first three postnatal days, the positive reaction for p21 was detected only in a small fraction of myocytes (12-20 %), a sudden increase in positivity occurred on day 4 (54 %) and continued till day 6 when the fraction of cells expressing p21 reached 87 %. Our results show that the induction of CDK inhibitor p21 in rat ventricular myocytes is developmentally regulated. Moreover, the fact that the sudden increase in p21 positivity occurred at the same stage when the myocyte proliferation rapidly ceases, suggests that this protein is likely to be involved in mediating this key event of cardiac development.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Myocardial m6A regulators in postnatal development: effect of sex
- Creator:
- Semenovykh, Dmytro, Benak, Daniel, Holzerova, Kristyna, Cerna, Barbora, Telensky, Petr, Vavrikova, Tereza, Kolar, Frantisek, Neckar, Jan, and Hlavackova, Marketa
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- epitranscriptomics, N6 -methyladenosine, postnatal development, and heart
- Language:
- English
- Description:
- N6 -methyladenosine (m6 A) is an abundant mRNA modification affecting mRNA stability and protein expression. It is a highly dynamic process, and its outcomes during postnatal heart development are poorly understood. Here we studied m6 A machinery in the left ventricular myocardium of Fisher344 male and female rats (postnatal days one to ninety; P1-P90) using Western Blot. A downward pattern of target protein levels (demethylases FTO and ALKBH5, methyltransferase METTL3, reader YTHDF2) was revealed in male and female rats during postnatal development. On P1, the FTO protein level was significantly higher in males compared to females.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. 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
5. Phospholipid composition in the rat heart exposed to pressure overload from birth
- Creator:
- mrnka, L., Nováková, O., Pelouch, V., and Novák, F.
- Type:
- article, model:article, and TEXT
- Subject:
- myocardium, pressure overload, aorta banding, hypertrophy, postnatal development, phospholipids, and plasmalogens
- Language:
- English
- Description:
- A pressure overload was induced in 2-day-old male rats by abdominal aortic constriction, and the phospholipid composition of the left ventricle (LV) and the right ventricle (RV) were determined. Sixty days after the surgery, body weights was lower and LV weight were higher in aorta-constricted (AC) rats in comparison with sham- operated animals. Increased ventricular/body weight ratios indicated a significant degree of hypertrophy of LV and smaller hypertrophy of RV. The concentrations of total phospholipids (PL), choline phosphoglycerides (PC), ethanolamine phosphoglycerides (PE), diphosphatidylglycerol (DPG) and phosphatidylinositol (PI) were decreased in both ventricles of AC rats. The concentrations of sphingomyelin (SM) and plasmalogen PE (PLPE) increased in LV only. The changes in phospholipid composition in the developing pressure-overloaded myocardium may contribute to altered membrane functions connected with heart hypertrophy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Plasma membrane density of GABAB-R1a, GABAB-R1b, Gaba-R2 and trimetic G-proteins in the course of postnatal development of rat brain cortex
- Creator:
- Dlouhá, K., Kagan, D., Roubalová, L., Ujčíková, H., and Svoboda, P.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, GABAB-R, postnatal development, rat brain cortex, g-proteins, Na, K-ATPase, 14, and 612
- Language:
- English
- Description:
- K. Dlouhá ... [et al.]. and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Pressure overload selectively increases n-3 PUFA in myocardial phospholipids during early postnatal period
- Creator:
- Novák, F., František Kolář, Voců, Š., Marek Vecka, and Olga Nováková
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, phospholipids, n-3 PUFA, myocardium, postnatal development, pressure overload, rat, 14, and 612
- Language:
- English
- Description:
- Increasing hemodynamic load during early postnatal development leads to rapid growth of the left ventricular (LV) myocardium, which is associated with membrane phospholipid (PL) remodeling characterized by n-3 polyunsaturated fatty acids (PUFA) accumulation. The aim of this study was to examine the influence of additional workload imposed early after birth when ventricular myocytes are still able to proliferate. Male Wistar rats were subjected to abdominal aortic constriction (AC) at postnatal day 2. Concentrations of PL and their fatty acid (FA) profiles in the LV were analyzed in AC, sham-operated (SO) and intact animals on postnatal days 2 (intact only), 5 and 10. AC resulted in LV enlargement by 22 % and 67 % at days 5 and 10, respectively, compared with age-matched SO littermates. Concentrations of phosphatidylcholine, cardiolipin, phosphatidylinositol, phosphatidylethanolamine, phosphatidylserine and sphingomyelin decreased in AC myocardium, albeit with different time course and extent. The main effect of AC on FA remodeling consisted in the accumulation of n-3 PUFA in PL. The most striking effect of AC on FA composition was observed in phosphatidylinositol and cardiolipin. We conclude that excess workload imposed by AC inhibited the normal postnatal increase of PL concentration while further potentiating the accumulation of n-3 PUFA as an adaptive response of the developing myocardium to accelerated growth., F. Novák, ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. The lipid peroxidation in various parts of the rat brain: effect of age, hypoxia and hyperoxia
- Creator:
- Koudelová, J. and Mourek, J.
- Type:
- article, model:article, and TEXT
- Subject:
- lipid peroxidation, rat brain, postnatal development, brain hypoxia, and brain hyperoxia
- Language:
- English
- Description:
- The effect of normobaric oxygen atmosphere on hypoxia-enhanced lipid peroxidation in the brain cortex, subcortical structures, medulla oblongata and in the cerebellum was observed in 7- and 21-day-old and adult rats. The production of free oxygen radicals causing lipid peroxidation was assessed by the method described by Ohkawa et al. (1979). The rats were exposed for 30 min to 100 % oxygen atmosphere which significantly stimulated the production of malondialdehyde (MDA) in all the studied regions of the brain in 7- and 21-day-old male rats, and in the brain cortex and subcortical structures of adult males. Higher levels of MDA were found in the brain cortex of 7-day-old female rats only. Reoxygenation with pure oxygen after 30 min hypobaric hypoxia corresponding to 9000 m increased MDA production in all studied parts of the brain on both male and female rats 7- and 21-day-old. In adult rats significantly increased MDA production was only found in the brain cortex of male and female rats and in the subcortical structures of males. The exposition to hypobaric hypoxia followed by reoxygenation by atmospheric air enhanced MDA production in all studied regions of the brain in 7-day-old males and in the cerebellum of females; in 21-day-old rats of both sexes a significant increase of MDA was detected in all parts of the brain. In adult rats were found higher MDA levels in the cerebral cortex of both males and females.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. Transient upregulation of protein kinase C in pressure-overloaded neonatal rat myocardium
- Creator:
- Blanka Hamplová, František Novák, František Kolář, and Olga Nováková
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, proteinové kinázy, protein kinases, protein kinase C, pressure overload, postnatal development, rat myocardium, 14, and 612
- Language:
- English
- Description:
- Protein kinase C (PKC) appears to play a significant role in the signal transduction of cardiac growth and development. The aim of this study was to determine changes in the total PKC activity and the expression of PKC isoforms α, δ and ε in the rat heart that was affected by pressure overload imposed at postnatal day (d) 2. Three groups of Wistar rats were employed for the experiment: rats submitted to the abdominal aortic constriction (AC), sham-operated controls (SO) and intact controls. Animals were sacrificed at d2, d3, d5 and d10. The total PKC activity was measured by the incorporation of 32P into histone IIIS and the expression of PKC was analyzed by immunoblotting in the homogenate of the left ventricular myocardium and in the cytosolic, membrane-enriched (105 × g) and nuclear-cytoskeletalmyofilament- enriched (103 × g) fractions. We observed the significant transient increase in both the total PKC activity and the expression of all isoforms at d5 (the 3rd day after the operation) in the cardiac homogenate of AC rats as compared with SO animals. Aortic constriction did not significantly affect the distribution of activity and isoform abundance among individual cellular fractions except for PKCδ, which increased significantly at d10 in the cytosolic fraction at the expense of the membraneenriched fraction. It is concluded that PKCα, PKCδ and PKCε undergo transient upregulation associated with the accelerated cardiac growth induced by pressure overload imposed in the very early postnatal period., B. Hamplová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public