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Start Over Creator Nováková, O.

2. Differences in heart phospholipids in two inbred rat strains differing in sensitivity to the development of heart lesions

Creator:
Kmoníčková, E., Nováková, O., Tvrzická, E., Mráz, M., and Hynie, S.
Type:
article, model:article, and TEXT
Subject:
hear, rat, phospholipids, fatty acids, and catecholamine-induced heart lesions
Language:
English
Description:
The content of phospholipids and their fatty acid composition were followed in the hearts of two inbred strains of rats: IR, resistant against the development of isoprenaline-induced myocardial lesions and IS, sensitive to their development. In the hearts of rats of the resistant strain, a lower content of phosphatidylcholine and its plasmalogen fraction was found compared to IS rats. The total amount of phospholipids was only insignificantly lower in IR rats. Greater differences were found in individual fatty acids. The most important finding concerned lower arachidonic acid and higher linoleic acid content in heart phospholipids of IR rats. These differences were exactly opposite to changes reported in the literature in animals known to have a higher resistance against myocardial damage due to various interventions. Our results do not support the hypothesis claiming the importance of changes in phospholipids and their FA composition for the resistance of the heart against the development of necrotic lesions.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Involvement of PKCε in cardioprotection induced by adaptation to chronic continuous hypoxia

Creator:
Holzerová, K., Hlaváčková, M., Jitka Žurmanová, Gudrun Borchert, Jan Neckář, Kolář, F., Novák, F., and Nováková, O.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, hypoxie, proteinové kinázy, hypoxia, protein kinases, chronic hypoxia, cardioprotection, ventricular myocytes, protein kinase C, PKCε inhibitory peptide KP-1633, 14, and 612
Language:
English
Description:
Continuous normobaric hypoxia (CNH) renders the heart more tolerant to acute ischemia/reperfusion injury. Protein kinase C (PKC) is an important component of the protective signaling pathway, but the contribution of individual PKC isoforms under different hypoxic conditions is poorly understood. The aim of this study was to analyze the expression of PKCε after the adaptation to CNH and to clarify its role in increased cardiac ischemic tolerance with the use of PKCε inhibitory peptide KP-1633. Adult male Wistar rats were exposed to CNH (10 % O2, 3 weeks) or kept under normoxic conditions. The protein level of PKCε and its phosphorylated form was analyzed by Western blot in homogenate, cytosolic and particulate fractions; the expression of PKCε mRNA was measured by RT-PCR. The effect of KP-1633 on cell viability and lactate dehydrogenase (LDH) release was analyzed after 25-min metabolic inhibition followed by 30-min reenergization in freshly isolated left ventricular myocytes. Adaptation to CNH increased myocardial PKCε at protein and mRNA levels. The application of KP-1633 blunted the hypoxiainduced salutary effects on cell viability and LDH release, while control peptide KP-1723 had no effect. This study indicates that PKCε is involved in the cardioprotective mechanism induced by CNH., K. Holzerová, M. Hlaváčková, J. Žurmanová, G. Borchert, J. Neckář, F. Kolář, F. Novák, O. Nováková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Low-salt diet alters the phospholipid composition of rat colonocytes

Creator:
Mrnka, L., Nováková, O., Novák, F., Eva Tvrzická, and Jiří Pácha
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, mastné kyseliny, fatty acids, aldosterone, phospholipid metabolism, 14, and 612
Language:
English
Description:
a1_The effect of low-salt diet on phospholipid composition and remodeling was examined in rat colon which represents a mineralocorticoid target tissue. To elucidate this question, male Wistar rats were fed a low-salt diet and drank distilled water (LS, low-salt group) or saline instead of water (HS, high-salt group) for 12 days before the phospholipid concentration and fatty acid composition of isolated colonocytes were examined. The dietary regimens significantly influenced the plasma concentration of aldosterone which was high in LS group and almost zero in HS group. Plasma concentration of corticosterone was unchanged. When expressed in terms of cellular protein content, a significantly higher concentration of phospholipids was found in LS group, with the exception of sphingomyelin (SM) and phosphatidylserine (PS). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) accounted for more than 70 % of total phospholipids in both groups. A comparison of phospholipid distribution in LS and HS groups demonstrated a higher percentage of PE and a small, but significant, decrease of PC and SM in LS group. The percentage of phosphatidylinositol (PI), PS and cardiolipin (CL) were not affected by mineralocorticoid treatment. With respect to the major phospholipids (PE, PC), a higher level of n-6 polyunsaturated fatty acids (PUFA) and lower levels of monounsaturated fatty acids were detected in PC of LS group. The increase of PUFA predominantly reflected an increase in arachidonic acid by 53%. In comparison to the HS group, oleic acid content was decreased in PC and PE isolated from colonocytes of the LS group. Our data indicate that alterations in phospholipid concentration and metabolism can be detected in rats with secondary hyperaldosteronism., a2_The changes in phospholipid concentration and their fatty acid composition during fully developed effect of low dietary Na+ intake may reflect a physiologically important phenomenon with long-term consequences for membrane structure and function., L. Mrnka, O. Nováková, F. Novák, E. Tvrzická , J. Pácha., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. N-acetylcysteine treatment prevents the up-regulation of Mn SOD in chronically hypoxic rat hearts

Creator:
Balková, P., Hlaváčková, M., Marie Milerová, Jan Neckář, František Kolář, Novák, F., and Nováková, O.
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, ischemie, infarkt myokardu, ischemia, myocardial infarction, chronic hypoxia, MnSOD, ischemia/reperfusion, cardioprotection, 14, and 612
Language:
English
Description:
Chronic intermittent hypoxia (CIH ) is associated with increased production of reactive oxygen species that contributes to the adaptive mechanism underlying the improved myocardial ischemic tolerance. The aim was to find out whether the antioxidative enzyme manganese superoxide dismutase (MnSOD) can play a role in CIH-induced cardioprotection. Adult male Wistar rats were exposed to intermittent hypobaric hypoxia (7000 m, 8 h/day, 25 exposures) (n=14) or kept at normoxia (n=14). Half of the animals from each group received N-acetylcysteine (NAC, 100 mg/kg) daily before the hypoxic exposure. The activity and expression of MnSOD were increased by 66 % and 23 %, respectively, in the mitochondrial fraction of CIH hearts as compared with th e normoxic group; these effects were suppressed by NAC treatment. The negative correlation between MnSOD activity and myoc ardial infarct size suggests that MnSOD can contribute to the improved ischemic tolerance of CIH hearts., P. Balková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. 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

7. Phospholipid Composition of Myocardium in Children with Normoxemic and Hypoxemic Congenital Heart Diseases

Creator:
Hamplová, B., Pelouch, V., Nováková, O., Škovránek, J., Hučín, B., and Novák, F.
Type:
article, model:article, and TEXT
Subject:
Phospholipids, Human myocardium, Congenital heart disease, Ventricle, and Atrium
Language:
English
Description:
Samples of myocardial tissue were obtained during cardiac surgery from children operated for different types of normoxemic and hypoxemic congenital heart diseases. The phospholipid composition was analyzed by thin layer chromatography. The concentration of total phospholipids (PL), phosphatidylcholine and phosphatidylethanolamine (PE) was found lower in atrial tissue of both normoxemic and hypoxemic groups in comparison with the ventricles. When comparing the difference between hypoxemic and normoxemic defects, hypoxemia was found to increase the concentration of total PL, PE and phosphatidylserine in ventricles and total PL and PE in the atria. The increased level of particular phospholipid species may represent adaptive mechanisms to hypoxemia in children with congenital heart diseases.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Regulation of phospholipid degradation and biosynthesis in the heart by isoprénaline: effect of mepacrine

Creator:
Nováková, O., Drnková, J., Kubišta, V., and Novák, F.
Type:
article, model:article, and TEXT
Subject:
phospholipids, mepacrine, isoprénaline, and heart
Language:
English
Description:
We investigated the effect of isoprénaline (IPRO), a /J-mimetic catecholamine, on incorporation of (32P)Pi into phospholipids of the mouse left ventricle in uiuo. All experimental groups of male mice received an injection of (32p)pi ^250 MBq x kg“1 b.w.) intraperitoneally two hours prior to sacrifice. A single dose of IPRO (5 mg x kg-1 b.w.) was injected one hour before killing. IPRO increased the specific radioactivity of phosphatidylcholine (PC) by a factor of 1.8, diphosphatidylglycerol (DPG) 2.1, sphingomyelin (SM) 3.5, phosphatidylinositol (PI) 1.7, phosphatidylserine (PS) 1.7, phosphatidylglycerol (PG) 1.7, phosphatidic acid (PA) 2.0 compared to control values. On the other hand, IPRO is also known to stimulate phospholipid degradation by activation of phospholipase A2. That is why we used mepacrine (50 mg x kg“1 b.w.), a phospholipase inhibitor, to find a possible link between biosynthesis and degradation of phospholipids. Pretreatment with mepacrine two hours prior to sacrifice suppressed IPRO stimulated incorporation of (32P)Pi into phospholipids nearly to control levels. Mepacrine itself did not significantly influence the specific radioactivity of phospholipids. We conclude that phospholipase A2 inhibitor, mepacrine, is able to prevent IPRO-stimulated ¡corporation into phospholipids, suggesting a feedback relation between their biosynthesis and degradation in the myocardium.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public