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Wyszukujesz frazę "Marciniak, Jerzy" wg kryterium: Wszystkie pola


Wyświetlanie 1-3 z 3
Tytuł:
Time-dependent effect of leptin on renal Na+,K+-ATPase activity
Autorzy:
Marciniak, Andrzej
Jamroz-Wiśniewska, Anna
Borkowska, Ewelina
Bełtowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1041321.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mitogen-activated protein kinases
leptin
obesity
arterial hypertension
hydrogen peroxide
Na+,K+-ATPase
Opis:
Leptin, secreted by adipose tissue, is involved in the pathogenesis of arterial hypertension, however, the mechanisms through which leptin increases blood pressure are incompletely elucidated. We investigated the effect of leptin, administered for different time periods, on renal Na+,K+-ATPase activity in the rat. Leptin was infused under anesthesia into the abdominal aorta proximally to the renal arteries for 0.5-3 h. Leptin administered at doses of 1 and 10 µg/min per kg for 30 min decreased the Na+,K+-ATPase activity in the renal medulla. This effect disappeared when the hormone was infused for ≥1 h. Leptin infused for 3 h increased the Na+,K+-ATPase activity in the renal cortex and medulla. The stimulatory effect was abolished by a specific inhibitor of Janus kinases (JAKs), tyrphostin AG490, as well as by an NAD(P)H oxidase inhibitor, apocynin. Leptin increased urinary excretion of hydrogen peroxide (H2O2) between 2 and 3 h of infusion. The effect of leptin on renal Na+,K+-ATPase and urinary H2O2 was augmented by a superoxide dismutase mimetic, tempol, and was abolished by catalase. In addition, infusion of H2O2 for 30 min increased the Na+,K+-ATPase activity. Inhibitors of extracellular signal regulated kinases (ERKs), PD98059 or U0126, prevented Na+,K+-ATPase stimulation by leptin and H2O2. These data indicate that leptin, by acting directly within the kidney, has a delayed stimulatory effect on Na+,K+-ATPase, mediated by JAKs, H2O2 and ERKs. This mechanism may contribute to the abnormal renal Na+ handling in diseases associated with chronic hyperleptinemia such as diabetes and obesity.
Źródło:
Acta Biochimica Polonica; 2005, 52, 4; 803-809
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nitric oxide - superoxide cooperation in the regulation of renal Na+,K+-ATPase.
Autorzy:
Bełtowski, Jerzy
Marciniak, Andrzej
Jamroz-Wiśniewska, Anna
Borkowska, Ewelina
Powiązania:
https://bibliotekanauki.pl/articles/1041505.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
H+,K+-ATPase
Sch 28080
superoxide anion
Na+,K+-ATPase
nitric oxide
oxidative stress
Opis:
The aim of this study was to investigate whether endogenous superoxide anion is involved in the regulation of renal Na+,K+-ATPase and ouabain-sensitive H+,K+-ATPase activities. The study was performed in male Wistar rats. Compounds modulating superoxide anion concentration were infused under general anaesthesia into the abdominal aorta proximally to the renal arteries. The activity of ATPases was assayed in isolated microsomal fraction. We found that infusion of a superoxide anion-generating mixture, xanthine oxidase (1 mU/min per kg) + hypoxanthine (0.2 μmol/min per kg), increased the medullary Na+,K+-ATPase activity by 49.5% but had no effect on cortical Na+,K+-ATPase and either cortical or medullary ouabain-sensitive H+,K+-ATPase. This effect was reproduced by elevating endogenous superoxide anion with a superoxide dismutase inhibitor, diethylthiocarbamate. In contrast, a superoxide dismutase mimetic, TEMPOL, decreased the medullary Na+,K+-ATPase activity. The inhibitory effect of TEMPOL was abolished by inhibitors of nitric oxide synthase (L-NAME), soluble guanylate cyclase (ODQ) and protein kinase G (KT5823). The stimulatory effect of diethylthiocarbamate was not observed in animals pretreated with a synthetic cGMP analogue, 8-bromo-cGMP. An inhibitor of NAD(P)H oxidase, apocynin (1 μmol/min per kg), decreased the Na+,K+-ATPase activity in the renal medulla and its effect was prevented by L-NAME, ODQ or KT5823. In contrast, a xanthine oxidase inhibitor, oxypurinol, administered at the same dose was without effect. These data suggest that NAD(P)H oxidase-derived superoxide anion increases Na+,K+-ATPase activity in the renal medulla by reducing the availability of NO. Excessive intrarenal generation of superoxide anion may upregulate medullary Na+,K+-ATPase leading to sodium retention and blood pressure elevation.
Źródło:
Acta Biochimica Polonica; 2004, 51, 4; 933-942
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bidirectional regulation of renal cortical Na+,K+-ATPase by protein kinase C.
Autorzy:
Bełtowski, Jerzy
Marciniak, Andrzej
Jamroz-Wiśniewska, Anna
Borkowska, Ewelina
Wójcicka, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/1041555.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
phosphatidylinositol-3-kinase
protein kinase C
cytochrome P450-dependent arachidonate metabolites
Na+,K+-ATPase
Opis:
We examined the role of protein kinase C (PKC) in the regulation of Na+,K+- ATPase activity in the renal cortex. Male Wistar rats were anaesthetized and the investigated reagents were infused into the abdominal aorta proximally to the renal arteries. A PKC-activating phorbol ester, phorbol 12,13-dibutyrate (PDBu), had a dose-dependent effect on cortical Na+,K+-ATPase activity. Low dose of PDBu (10-11 mol/kg per min) increased cortical Na+,K+-ATPase activity by 34.2%, whereas high doses (10-9 and 10-8 mol/kg per min) reduced this activity by 22.7% and 35.0%, respectively. PDBu administration caused changes in Na+,K+-ATPase Vmax without affecting K0.5 for Na+, K+ and ATP as well as Ki for ouabain. The effects of PDBu were abolished by PKC inhibitors, staurosporine, GF109203X, and Gö 6976. The inhibitory effect of PDBu was reversed by pretreatment with inhibitors of cytochrome P450-dependent arachidonate metabolism, ethoxyresorufin and 17-octadecynoic acid, inhibitors of phosphatidylinositol 3-kinase (PI3K), wortmannin and LY294002, and by actin depolymerizing agents, cytochalasin D and latrunculin B. These results suggest that PKC may either stimulate or inhibit renal cortical Na+,K+-ATPase. The inhibitory effect is mediated by cytochrome P450-dependent arachidonate metabolites and PI3K, and is caused by redistribution of the sodium pump from the plasma membrane to the inactive intracellular pool.
Źródło:
Acta Biochimica Polonica; 2004, 51, 3; 757-772
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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