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001-es BibID:	BIBFORM006034
Első szerző:	Gáspár Rezső (biofizikus)
Cím:	Bretylium-induced voltage-gated sodium current in human lymphocytes / Rezső Gáspár, Zoltán Krasznai, Teréz Márián, Lajos Trón, Rina Recchioni, Marco Falasca, Fausto Moroni, Carlo Pieri, Sándor Damjanovich
Dátum:	1992
ISSN:	0167-4889
Megjegyzések:	Using the whole-cell variation of the patch-clamp technique it has been determined that 0.25-3 mM bretylium tosylate (BT) exerts a repolarizing effect on partially depolarized human lymphocytes. The repolarizing effect was ouabain (40 microM)-sensitive, and was inhibited by the removal of external Na+ or by the Na(+)-channel-blocker amiloride (10-44 microM), but K(+)-channel-blockers 4-aminopyridine (0.1-5 mM) and quinine (100 microM) had no effect. The drug induced a sodium dependent, amiloride-sensitive transient inward current reaching its maximum value approx. 20-30 s after the administration of BT and lasting for 6-10 min. This current was activated by depolarization within 25 ms at around -42 mV, its inactivation took about 2 s and its reversal potential was +24 +/- 5 mV. An increase in the intracellular sodium concentration (1.8-3.2 mM) has been observed upon the addition of BT by monitoring the SBFI fluorescence of the dye-loaded cells. It has been shown that whole-cell K+ currents are significantly decreased by BT. The existence of voltage and ligand (BT)-gated sodium channels has been postulated in human lymphocytes. These channels are thought to participate in the initiation of membrane repolarization in human lymphocytes, and thereby influence mitogenic or antigen-induced cell-activation processes.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Bretylium Ion channel Patch-clamp Human lymphocyte
Megjelenés:	Biochimica et Biophysica Acta (BBA). Molecular Cell Research. - 1137 : 2 (1992), p. 143-147. -
További szerzők:	Krasznai Zoltán (1950-) (biofizikus) Márián Teréz (1950-) (radiobiológus) Trón Lajos (1941-) (biofizikus) Recchioni, Rina Falasca, Marco Moroni, Fausto Pieri, Carlo Damjanovich Sándor (1936-2017) (biofizikus)
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001-es BibID:	BIBFORM005987
Első szerző:	Pieri, Carlo
Cím:	Ligand and voltage gated sodium channels may regulate electrogenic pump activity in human, mouse and rat lymphocytes / C. Pieri, R. Recchioni, F. Moroni, L. Balkay, T. Márián, L. Trón, S. Damjanovich
Dátum:	1989
Megjegyzések:	Bretylium tosylate - a sodium channel opener - resulted in an increase of membrane potential of depolarized human, rat and mouse T and B lymphocytes. Flow cytometric membrane potential measurements with bis-oxonol revealed that the above hyperpolarizing effect was amiloride, ouabain, tetrodotoxin, azide and temperature sensitive. The effect showed an absolute dependence on the extracellular sodium but it was insensitive to the extracellular Ca2+ level. The voltage gating of the effect can be eliminated by either an increase of the extracellular potassium concentration or low doses of veratrin. The existence of a voltage and ligand gated sodium channel is suggested in the plasma membrane of all kinds of lymphocytes. The hyperpolarization is explained by an increased activity of the electrogenic sodium-potassium ATP-ase. Induced opening of such sodium channels may regulate the electrogenic pump activity and indirectly cell activation.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Amiloride Animal B-Lymphocytes Bretylium Tosylate Calcium Cell Membrane drug effects Dyes Electrochemistry Female Flow Cytometry Fluorescent Dyes Human Lymphocytes Membrane Potentials Mice Mice,Inbred BALB C Mice,Nude pharmacology physiology Potassium Rats Sodium Sodium Channels Support,Non-U.S.Gov't Tetrodotoxin Thiobarbiturates
Megjelenés:	Biochemical and Biophysical Research Communications. - 160 : 3 (1989), p. 999-1002. -
További szerzők:	Recchioni, Rina Moroni, Fausto Balkay László (1963-) (biofizikus) Márián Teréz (1950-) (radiobiológus) Trón Lajos (1941-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:	elektronikus változat
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001-es BibID:	BIBFORM006056
Első szerző:	Trón Lajos (biofizikus)
Cím:	Bretylium causes a K(+)-Na+ pump activation that is independent of Na+/H+ exchange in depolarized rat, mouse and human lymphocytes / Tron, L., Pieri, C., Marian, T., Balkay, L., Emri, M., Damjanovich, S.
Dátum:	1990
Megjegyzések:	We have studied a bretylium tosylate induced increase of the membrane potentials of partially depolarized rat, mouse and human lymphocytes, using the potential sensitive dye, bis [1,3, dibutylbarbituric acid-(5) trimethine oxonol]. The extent of this repolarization is dose-dependent and decreased in magnitude as the temp was reduced from 37 degrees C to room temp. The repolarizing effect is inhibited by K(+)-Na(+)-pump blockers or lack of extracellular Na+. Sodium ion channel blockers are effective in abolishing repolarization only if applied prior to, or simultaneously with, bretylium. Activation of Na+/H+ exchange is not involved in the mechanism of the phenomenon as the latter is completely eliminated in the presence of 10 microM amiloride (concn of the diuretics having no measurable inhibition on the action of the exchanger). These data suggest that bretylium opens ligand- and voltage-gated Na+ channels, and repolarization occurs due to higher activity of the K(+)-Na(+)-pump stimulated by the enhanced intracellular Na+ accumulation.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Animal Bretylium Compounds Bretylium Tosylate drug effects Human Hungary In Vitro Lymphocytes Membrane Potentials metabolism Mice Na(+)-K(+)-Exchanging ATPase pharmacology physiology Potassium Protons Rats Rats,Inbred Strains Sodium Support,Non-U.S.Gov't
Megjelenés:	Molecular Immunology. - 27 : 12 (1990), p. 1307-1311. -
További szerzők:	Pieri, Carlo Márián Teréz (1950-) (radiobiológus) Balkay László (1963-) (biofizikus) Emri Miklós (1962-) (fizikus) Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:	elektronikus változat
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