Wyniki wyszukiwania

1

Transcellular and paracellular routes of ion transport across human bronchial epithelium

100%

Dolowy K.

Current Topics in Biophysics. Supplement

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2013

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tom 36

|

nr 2A: Plenary lectures

2

A new double-chamber model of ion channels. Beyond the Hodgkin and Huxley model

100%

Dolowy K.

Cellular and Molecular Biology Letters

|

2003

|

tom 08

|

nr 3

This paper proposes a new double-chamber model (DCM) of ion channels. The model ion channel consists of a series of three pores alternating with two chambers. The chambers are net negatively charged. The chamber’s electric charge originates from dissociated amino acid side chains and is pH dependent. The chamber’s net negative charge is compensated by cations present inside the chamber and in a diffuse electric layer outside the chamber. The pore’s permeability is constant independent of time. One pore of the sodium channel and one of the potassium channel is a voltage-sensing pore. Due to the channel's structure, ions flow through the pores and chambers in a time-dependent manner. The model reproduces experimental voltage clamp and action potential data. The current flowing through a single sodium channel is less then one femtoampere. The DCM is considerably simpler then the Hodgkin and Huxley model (HHM) used to describe the electrophysiological properties of an axon. Unlike the HHM, the DCM can explain refractoriness, anode break excitation, accommodation and the effect of pH and temperature on the channels without additional parameters. In the DCM, the axon membrane shows repetitive activity depending on the channel density, sodium to potassium channel ratio and external potassium concentration. In the DCM, the action potential starts from ‘hot spot areas’ of higher channel densities and a higher sodium to potassium channel ratio, and then propagates through the whole axon.

3

Environmental toxins and ion channels

75%

Dolowy K.

Cellular and Molecular Biology Letters

|

2001

|

tom 06

|

nr 2A

343-347

4

Mikrofalowe suszenie drewna

63%

Zielonka P., Dolowy K.

Przemysł Drzewny

|

1997

|

tom 48

|

nr 11

7-11

5

Locomotory response of Amoeba proteus to Hplus and a protonophore (FCCP)

63%

Dolowy K., Grebecki A.

Acta Protozoologica

|

1988

|

tom 27

|

nr 2

6

Ion channels-related diseases

63%

Dworakowska B., Dolowy K.

Acta Biochimica Polonica

|

2000

|

tom 47

|

nr 3

There are many diseases related to ion channels. Mutations in muscle voltage-gated sodium, potassium, calcium and chloride channels, and acetylcholine-gated channel may lead to such physiological disorders as hyper- and hypokalemic periodic paralysis, myotonias, long QT syndrome, Brugada syndrome, malignant hyperthermia and myasthenia. Neuronal disorders, e.g., epilepsy, episodic ataxia, familial hemiplegic migraine, Lambert-Eaton myasthenic syndrome, Alzheimer's disease, Parkinson's disease, schizophrenia, hyperekplexia may result from dysfunction of voltage-gated sodium, potassium and calcium channels, or acetylcholine- and glycine-gated channels. Some kidney disorders, e.g., Bartter's syndrome, policystic kidney disease and Dent's disease, secretion disorders, e.g., hyperinsulinemic hypoglycemia of infancy and cystic fibrosis, vision disorders, e.g., congenital stationary night blindness and total colour-blindness may also be linked to mutations in ion channels.

7

Single channel measurements of ATP regulated potassium channel from rat brain mitochondria

51%

Choma K., Bednarczyk P., Szewczyk A., Dolowy K.

Acta Biochimica Polonica

|

2006

|

tom 53

|

nr Supplement 1

8

Potassium channel of inner membranes of cardiac mitochondria

51%

Bednarczyk P., Kicinska A., Dolowy K., Szewczyk A.

Acta Biochimica Polonica

|

2003

|

tom 50

|

nr Supplement 1

9

Multi-ion sensor system for real-time ion transport monitoring

51%

Toczylowska-Maminska R., Zajac M., Madej H., Dolowy K.

Current Topics in Biophysics. Supplement

|

2013

|

tom 36

|

nr 2A: Posters

10

Wplyw hormonow steroidowych na kinetyke nikotynowego receptora acetylcholiny

51%

Nurowska E., Dworakowska B., Dolowy K.

Postępy Higieny i Medycyny Doświadczalnej

|

2000

|

tom 54

|

nr 3

363-370

11

Integrated electrode system to study ion fluxes across the monolayer of epithelial cells grown on porous support

51%

Toczylowska-Maminska R., Zajac M., Lewenstam A., Dolowy K.

Acta Neurobiologiae Experimentalis

|

2012

|

tom 72

|

nr 2

Cystic fibrosis is the most common fatal human genetic disorder. It is caused by mutation of chloride channel protein called CFTR. CFTR channel plays a role in osmotic driven water transportacross epithelial cell monolayer. The defective water transport leads to dense viscous mucus secretion which blocks pancreatic juice production and the clearance of lung fluid. The viscous mucus leads to opportunistic infections in lungs which deteriorates its function. The simple explanation of the mechanism of fluid secretion and absorption in different epithelial tissue failed. Either there are different mechanisms for different epithelial tissues or other ion channels beside CFTR are involved in water transport. From that what is known from experimental studies across the lung epithelium sodium, potassium, protons, chloride and bicarbonateions are transported. To solve the mechanism of the mechanism of water transport we need to measure all the ion concentration changes, as fast as possible. Materials and methods: Silver wires were mounted in poly(methyl metacrylate)-based modules. Solid state ion selective electrodes and reference electrode has been used. In the preliminary studies the cell layer was replaced by a porous membrane of resistance of approximately 800 Ω•cm-2 similar to resistances of cell monolayers (300–1500 Ω•cm-2). Results show that we are able to detect ion flow across artificial membrane. Our integrated electrode system can be used to study epithelial cells. This work was supported by a grant from National Center of Science (NCN) grant No. N N401 182839.

12

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Visualization of wood humidity using cobalt chloride during microwave drying

51%

Zielonka P., Jarzabek W. A., Ksiazka P., Dolowy K.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

|

2015

|

tom 92

13

Application of membrane system for investigating sorption properties of halloysite

51%

Zajac M., Madej H., Toczylowska-Maminska R., Dolowy K.

Current Topics in Biophysics. Supplement

|

2013

|

tom 36

|

nr 2A: Posters

14

Potassium channel activity from bovine chromaffin granules

51%

Hordejuk R., Szewczyk A., Dolowy K.

Acta Biochimica Polonica

|

2003

|

tom 50

|

nr Supplement 1

15

Source of voltage-dependency in hydrocortisone block of nicotinic acetylcholine receptor

51%

Dworakowska B., Nurowska E., Dolowy K.

Acta Neurobiologiae Experimentalis

|

2018

|

tom 78

|

nr Suppl.1

Corticosteroids have been shown to exert direct inhib‑ itory action on the muscle‑type nicotinic acetylcholine re‑ ceptor (AChR) and therefore can promote pharmacological muscle denervation. The mechanism of hydrocortisone (HC) blockade of AChR has not been fully established. It is uncommon for an electrically neutral molecule, e.g. HC, to induce voltage‑dependent changes in AChR kinetics. Our experiments aimed to determine the source of voltage‑de‑ pendency in HC action. Wild‑type (WT) and αD200Q recep‑ tors were transiently expressed in HEK293 cells. Record‑ ings were performed in either the presence or absence of HC. We showed that the D‑to‑Q substitution is capable of suppressing voltage dependency in the HC‑induced block. We conclude that the distance between αD200 and the ago‑ nist binding site depends on the membrane potential. The voltage‑dependent changes of the αD200 position have not been determined yet. To our knowledge, the ability to in‑ duce voltage‑dependency in blocker action has not been shown previously for an amino acid located outside the transmembrane portion of the receptor. Possible mech‑ anisms of HC block (allosteric and knocking) in WT and αD200Q receptors are proposed.

16

Liposomes preparation and examination by electron microscopy and image analysis

51%

Zielonka P., Butryn M., Dolowy K., Gierlik E.

Annals of Warsaw Agricultural University. Forestry and Wood Technology

|

1994

|

tom 45

55-59

17

Multielectrode biosensor system for simultaneuos measurements of ion fluxes across the epithelial cells

51%

Zajac M., Lewenstam A., Dolowy K.

Current Topics in Biophysics. Supplement

|

2016

|

tom 39

|

nr A: Plenary lectures

18

pH and nucleotide modulation of mitochondrial ATP-regulated potassium channel

51%

Bednarczyk P., Dolowy K., Szewczyk A.

Acta Biochimica Polonica

|

2007

|

tom 54

|

nr Supplement 4

19

The relationship between extracellular K-plus and Ca2-plus on aminopyrine accumulation in rat parietal cells

51%

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

Journal of Physiology and Pharmacology

|

1991

|

tom 42

|

nr 3

The effects of extracellular K⁺ in relation to extracellular Ca²⁺ on acid production were studied. Studies were performed in vitro using isolated cells from rat stomachs, and acid production was indirectly determined by ¹⁴C-aminopyrine (AP) accumulation. In the absence of K⁺ in the incubation medium histamine-stimulated AP accumulation ratios were significantly decreased independently in the presence or absence of extracellular Ca²⁺. Under basal conditions, in the absence of extracellular Ca²⁺ , increasing concentrations of extracellular K⁺ enhanced AP accumulation ratios to significantly higher than those found in the presence of Ca²⁺. In histamine-, cAMP-, and carbachol-stimulated parietal cells, high K⁺ concentrations increased AP accumulation significantly less in Ca²⁺-free than in Ca²⁺-containing media. High K⁺ also induced significantly both an increase in cytosolic free Ca²⁺ concentration and ⁴⁵ Ca²⁺ uptake. The present results confirmed the importance of K⁺ in gastric acid production and suggested a role for Ca²⁺ as a modulator of mechanisms of parietal cell stimulation.

20

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

51%

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

Journal of Physiology and Pharmacology

|

1991

|

tom 42

|

nr 4

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.

Ograniczanie wyników

Transcellular and paracellular routes of ion transport across human bronchial epithelium

A new double-chamber model of ion channels. Beyond the Hodgkin and Huxley model

Environmental toxins and ion channels

Mikrofalowe suszenie drewna

Locomotory response of Amoeba proteus to Hplus and a protonophore (FCCP)

Ion channels-related diseases

Single channel measurements of ATP regulated potassium channel from rat brain mitochondria

Potassium channel of inner membranes of cardiac mitochondria

Multi-ion sensor system for real-time ion transport monitoring

Wplyw hormonow steroidowych na kinetyke nikotynowego receptora acetylcholiny

Integrated electrode system to study ion fluxes across the monolayer of epithelial cells grown on porous support

Visualization of wood humidity using cobalt chloride during microwave drying

Application of membrane system for investigating sorption properties of halloysite

Potassium channel activity from bovine chromaffin granules

Source of voltage-dependency in hydrocortisone block of nicotinic acetylcholine receptor

Liposomes preparation and examination by electron microscopy and image analysis

Multielectrode biosensor system for simultaneuos measurements of ion fluxes across the epithelial cells

pH and nucleotide modulation of mitochondrial ATP-regulated potassium channel

The relationship between extracellular K-plus and Ca2-plus on aminopyrine accumulation in rat parietal cells

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