Wyniki wyszukiwania - Biblioteka Nauki

1

Liver mitochondria and insulin resistance

100%

Vial G. , Dubouchaud H. , Leverve X. M.

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nr 4

389-392

EN

With a steadily increasing prevalence, insulin resistance (IR) is a major public health issue. This syndrome is defined as a set of metabolic dysfunctions associated with, or contributing to, a range of serious health problems. These disorders include type 2 diabetes, metabolic syndrome, obesity, and non-alcoholic steatohepatitis (NASH). According to the literature in the field, several cell types like β-cell, myocyte, hepatocyte and/or adipocyte, as well as related complex signaling environment involved in peripheral insulin sensitivity are believed to be central in this pathology. Because of the central role of the liver in the whole-body energy homeostasis, liver insulin sensitivity and its potential relationship with mitochondrial oxidative phosphorylation appear to be crucial. The following short review highlights how liver mitochondria could be implicated in IR and should therefore be considered as a specific therapeutic target in the future.

2

Does the membrane potential control incorporation of tubulovesicles into the secreting apical membrane of the rat parietal cell?

88%

Ostrowski J. , Dolowy K. , Zych W. , Butruk E.

Journal of Physiology and Pharmacology

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1991

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tom 42

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nr 4

EN

The present studies were designed to examine the effect of changes in membrane potential by means of protonophore carbonyl cyanide m-chlorophenylhydrazone (СССР) and variations in the pH of the medium on the secretory response of parietal cells. Studies were performed in vitro using isolated cells from rat stomachs and acid production was indirectly determined by ¹⁴C-aminopyrine (AP) accumulation. СССР affected both basal and histamine-stimulated AP accumulation in a concentration-dependent manner. The AP accumulation ratios depended on pH of the incubation medium; the ratio was lowest at pH 6.6, and increased progressively as the pH of the medium increased to 7.8. Moreover, the decreases in AP accumulation ratios caused by simultanous addition of СССР and AP to cell suspensions compared to those in which СССР was added to incubated cells after achieving the steady-state of AP accumulation were quantitatively similar. These findings suggest that the decrease in AP accumulation due to СССР treaiment is a consequence of an activation of acid secretion rather than an inhibitor of acid production. From the present and previously published data, we propose a working hypothesis: membrane recycling is dependent on changes in apical membrane potential.

3

Fluctuations of lipid-like membranes potential induced by glycine esters

88%

Podolak M. , Kocherginsky N. M. , Osak I. S. , Przestalski S.

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1994

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tom 12

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nr 2

4

Effects of quercetin and verapamil on membrane potential in the liverwort Conocephalum conicum

75%

Pawlikowska-Pawlega B. , Trebacz K. , Krol E. , Gawron A.

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nr 1

5

Differentiated Paju cells have increased resistance to toxic effects of potassium ionophores

63%

Teplova V. , Jaaskelainen E. , Salkinoja-Salonen M. , Saris N. E. L. , Serlachius M. , Li F. Y. , Andersson L. C.

Acta Biochimica Polonica

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2004

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tom 51

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nr 2

EN

In this study we have investigated the impact of differentiation of neuronal cells on their sensitivity to microbial toxins. We used the human neural crest-derived tumor cell line Paju, which can be induced to differentiation in vitro by treatment with phorbol 12-myristate 13-acetate. Addition of the highly toxic potassium ionophores cereulide (4.5 and 9.0 ng/ml) or valinomycin (20 ng/ml), to cultures of undifferentiated Paju cells caused collapse of the mitochondrial membrane potential — measured with the fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetrabenzimidazole carbo- cyanine iodide (JC-1) followed by detachment of the cells and their apoptotic death. After induced differentiation of the Paju cells, their mitochondria retained the membrane potential upon exposure to the toxins and the cells displayed increased resistance to apoptosis as compared with undifferentiated cells. This effect may be caused by an elevated expression of the anti-apoptotic protein Bcl-2 and of the neuroprotective factor, stanniocalcin, in differentiated cells.

6

Reakcja fotoelektryczna śluzowca Physarum polycephalum i jej związek z zakwaszaniem środowiska

51%

Pazurkiewicz-Kocot K. , Stolarek J.

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tom 17

7

In vitro recorded theta-like activity in the limbic cortex: comparison with spontaneous theta and epileptiform discharges

51%

Konopacki J. , Golebiewski H. , Eckersdorf B. , Kowalczyk T. , Bocian R.

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nr 1

EN

The generation of EEG theta rhythm in the mammalian limbic cortex is a prime example of rhythmic activity that involves central mechanisms of oscillations and synchrony. This EEG pattern has been extensively studied since 1938, when Jung and Kornmuller (1938) demonstrated the first theta recordings in the hippocampal formation of rabbits. In 1986 in collaboration with Drs. B.H. Bland, S.H. Roth and B.M. Maclver we demonstrated for the first time that bath perfusion of hippocampal slices with the cholinergic agonist, carbachol, resulted in theta-like oscillations. Since this initial demonstration of in vitro theta-like activity, we have carried out a number of experiments in an attempt to answer the basic question: what are the similarities between cholinergic-induced in vitro theta-like activity and theta rhythm which naturally occurs in the in vivo preparation. Thus far, our studies have provided strong evidence that theta-like activity recorded in vitro shares many of the physiological and pharmacological properties of theta rhythm observed in vivo. The question whether in vitro theta-like oscillations reflect features of epileptiform activity is also adressed in this review.

8

Energetic coupling in mitochondria of a slime mould Dictyostelium discoideum

51%

Michejda J. , Budzinska M. , Marcinkowska A. , Hryniewiecka L.

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tom 34

9

Co-involvement of the mitochondria and endoplasmic reticulum in cell death induced by the novel ertargeted protein HAP

51%

Xu H. , Zhou Q. , Liu X. , Qi Y.

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nr 2

EN

HAP (a homologue of the ASY/Nogo-B protein), a novel human apoptosis-inducing protein, was found to be identical to RTN3. In an earlier study, we demonstrated that HAP localized exclusively to the endoplasmic reticulum (ER) and that its overexpression could induce cell apoptosis via a depletion of endoplasmic reticulum (ER) Ca2+ stores. In this study, we show that overexpression of HAP causes the activation of caspase-12 and caspase-3. We still detected the collapse of mitochondrial membrane potential (Δωm) and the release of cytochrome c in HAP-overexpressing HeLa cells. All the results indicate that both the mitochondria and the ER are involved in apoptosis caused by HAP overexpression, and suggest that HAP overexpression may initiate an ER overload response (EOR) and bring about the downstream apoptotic events.

10

Wpływ jonów kadmu na reakcję fotoelektryczną komórek Nitellopsis obtusa

44%

Stolarek J. , Kurtyka R. , Karcz W. , Mroczkowska-Badner E. , Malkowski E.

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tom 17

11

Działanie fitohormonów na potencjał membranowy, przyrost świeżej masy i pompę protonową w komórkach koleoptyli Triticum vulgare L.

38%

Stolarek J. , Zientara M.

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tom 17