Összesen 3 találat.


001-es BibID:BIBFORM039513
Első szerző:Márián Teréz (radiobiológus)
Cím:A1 and A2 adenosine receptor activation inversely modulates potassium currents and membrane potential in DDT1 MF-2 smooth muscle cells / Marian, T., Rubovszky, B., Szentmiklosi, A. J., Tron, L., Balkay, L., Boros, I., Gaspar, R., Szekely, A., Krasznai, Z.
Megjegyzések:Adenosine receptors are widely distributed in mammalian tissues and have been possibly involved through transmembrane potential changes in cell function regulation. The effect of A1 and A2A adenosine receptor ligands on transmembrane potential measured with flow cytometry and potassium conductance measured by the patch-clamp technique was investigated in DDT1 MF-2 smooth muscle cells. The A1 adenosine-receptor agonist CPA (50 nM) and the A2A adenosine-receptor agonist CGS 21680 (50 nM) elicited a rapid and maintained increase and decrease in the potassium conductance, respectively, and a concomitant hyperpolarization and depolarization of the membrane, respectively. These effects were eliminated by subtype-selective adenosine receptor antagonists (DPCPX, CSC, ZM 241385, all 1 microM). The ligand induced membrane potential changes were reversible. Based on these detected membrane potential changes along with the published voltage dependence of the adenylyl cyclase, the regulation of cAMP production by A1- and A2A-receptor activation is suggested to be mediated through the induced early hyperpolarization and depolarization. The interaction between the effects of these receptor subtypes allows for a complex regulation mechanism.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:The Japanese Journal of Pharmacology. - 89 : 4 (2002), p. 366-372. -
További szerzők:Rubovszky Bálint (1975-) (élettanász) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos) Trón Lajos (1941-) (biofizikus) Balkay László (1963-) (biofizikus) Boros István Gáspár Rezső (1944-) (biofizikus) Székely Andrea Krasznai Zoltán (1950-) (biofizikus)
Internet cím:Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM046089
Első szerző:Rubovszky Bálint (élettanász)
Cím:Comparative pharmacological studies on the A2 adenosine receptor agonist 5'-n-ethyl-carboxamidoadenosine and its F19 isotope labelled derivative / Rubovszky B., Szentmiklosi A. J., Marian T., Cseppento A., Gesztelyi R., Szekely A., Forizs F., Gaspar R., Tron L., Krasznai Z.
Megjegyzések:Adenosine receptors are expressed in various mammalian tissues where they mediate the effects of adenosine on cellular functions through a number of signalling mechanisms. 18F-NECA is the positron-emitting derivative of the A(2)-receptor agonist NECA (5'-n-ethyl-carboxamidoadenosine) and is a radioligand for PET imaging of adenosine receptors. Contractility and relaxation studies were performed on guinea pig atrial myocardium, pulmonary artery, and thoracic aorta to compare the pharmacological effects of NECA and F-NECA (a non-emitting derivative) on tissues. Furthermore, the effect of NECA and F-NECA on the potassium conductance was investigated in DDT1 MF-2 smooth muscle cells with the patch-clamp technique. Both NECA and F-NECA reduced the contractile force in atrial myocardium and evoked phasic contraction in pulmonary artery (A(1) adenosine-receptor-mediated actions) in a dose dependent manner; however, the apparent affinity was lower for F-NECA. No difference was found in relaxation induced by these compounds in 1 microM noradrenaline-precontracted aorta and pulmonary artery (in the presence of DPCPX, an A(1) adenosine receptor antagonist, tissue containing A(2B) adenosine receptors). NECA (5 microM) and F-NECA (5 microM) also decreased the peak current and accelerated activation and inactivation properties of the potassium channels, but F-NECA was less effective. These results suggest that while NECA and F-NECA are equivalent agonists of vascular A(2B) receptors, they mediate different changes of some parameters. When evaluating the data obtained by the use of radiolabelled ligands, one has to take into consideration the possible physiological effects of the ligands besides its binding properties to tissues.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Journal of Pharmacological Sciences. - 93 : 3 (2003), p. 356-363. -
További szerzők:Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos) Márián Teréz (1950-) (radiobiológus) Cseppentő Ágnes (1953-) (orvos) Gesztelyi Rudolf (1969-) (kísérletes farmakológus) Székely Andrea Forizs Fruzsina Gáspár Rezső (1944-) (biofizikus) Trón Lajos (1941-) (biofizikus) Krasznai Zoltán (1950-) (biofizikus)
Pályázati támogatás:T 043087
T 038270
Internet cím:Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM004884
Első szerző:Rubovszky Bálint (élettanász)
Cím:Detection of channel proximity by nanoparticle-assisted delaying of toxin binding : a combined patch-clamp and flow cytometric energy transfer study / Rubovszky, B., Hajdu, P., Krasznai, Z., Gaspar, R., Waldmann, T. A., Damjanovich, S., Bene, L.
Megjegyzések:Gold nanoparticles of 30 nm diameter bound to cell-surface receptor major histocompatibility complex glycoproteins (MHCI and MHCII), interleukin-2 receptor alpha subunit (IL-2Ralpha), very late antigen-4 (VLA-4) integrin, transferrin receptor, and the receptor-type protein tyrosin phosphatase CD45 are shown by the patch-clamp technique to selectively modulate binding characteristics of Pi(2) toxin, an efficient blocker of K(v)1.3 channels. After correlating the electrophysiological data with those on the underlying receptor clusters obtained by simultaneously conducted flow cytometric energy transfer measurements, the modulation was proved to be sensitive to the density and size of the receptor clusters, and to the locations of the receptors as well. Based on the observation that engagement of MHCII by a monoclonal antibody down-regulates channel current and based on the close nanometer-scale proximity of the MHCI and MHCII glycoproteins, an analogous experiment was carried out when gold nanoparticles bound to MHCI delayed down-regulation of the K(v)1.3 current initiated by ligation of MHCII. Localization of K(v)1.3 channels in the nanometer-scale vicinity of the MHC-containing lipid rafts is demonstrated for the first time. A method is proposed for detecting receptor-channel or receptor-receptor proximity by observing nanoparticle-induced increase in relaxation times following concentration jumps of ligands binding to channels or to receptors capable of regulating channel currents.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Cell Line
drug effects
Energy Transfer
Flow Cytometry
Interleukin-2 Receptor alpha Subunit
Ion Channel Gating
Kv1.3 Potassium Channel
Major Histocompatibility Complex
Particle Size
Patch-Clamp Techniques
Potassium Channels
Potassium Channels,Voltage-Gated
Protein Binding
Scorpion Venoms
Megjelenés:European Biophysics Journal. - 34 : 2 (2005), p. 127-143. -
További szerzők:Hajdu Péter (1975-) (biofizikus) Krasznai Zoltán (1950-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Waldmann, Thomas A. Damjanovich Sándor (1936-2017) (biofizikus) Bene László (1963-) (biofizikus)
Internet cím:elektronikus változat
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