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001-es BibID:	BIBFORM006036
Első szerző:	Gáspár Rezső (biofizikus)
Cím:	Effects of bretylium tosylate on voltage-gated potassium channels in human T lymphocytes / Gaspar, R., Panyi, G., Ypey, D. L., Krasznai, Z., Vereb, G., Pieri, C., Damjanovich, S.
Dátum:	1994
Megjegyzések:	Using the patch-clamp technique, we determined that bretylium tosylate, a quaternary ammonium compound possessing immunomodulating activity, decreased the whole-cell K+ current in human T lymphocytes, in a dose-dependent manner, in the 0.05-5 mM extracellular concentration range. Bretylium tosylate prolonged the recovery from inactivation and accelerated the inactivation and deactivation of the K+ current but did not influence the kinetics of activation or the voltage dependence of activation and steady state inactivation of the K+ conductance. The percentage of drug-induced block was independent of membrane potential. K+ channel block by bretylium tosylate was partially and slowly removable by washing with drug-free extracellular solution. Bovine serum albumin (10 mg/ml) in the bath lifted the drug-induced block almost instantaneously, although not completely. In control experiments bovine serum albumin increased the inactivation time constant of the K+ channels but left the peak K+ current amplitude unaffected. On the basis of the experimental evidence, a gating-dependent allosteric interaction is suggested for the mechanism of drug action. The effective dose range, time of exposure, and reversibility of bretylium tosylate-induced K+ channel block correlated well with the same parameters of the drug-induced inhibition of T lymphocyte activation. The reported effects of bretylium tosylate on T cell mitogenesis can be regarded partly as a consequence of its blocking effects on voltage-gated K+ channels.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Bretylium Tosylate Cell Membrane drug effects Electrophysiology Human Hungary In Vitro Ion Channel Gating Kinetics Lymphocytes pharmacology physiology Potassium Potassium Channels Support,Non-U.S.Gov't T-Lymphocytes
Megjelenés:	Molecular pharmacology. - 46 : 4 (1994), p. 762-766. -
További szerzők:	Panyi György (1966-) (biofizikus) Ypey, Dirk L. Krasznai Zoltán (1950-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Pieri, Carlo Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:	elektronikus változat
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001-es BibID:	BIBFORM006058
Első szerző:	Weidema, Adam Freek (biofizikus)
Cím:	A Ca2+-dependent K+-channel in freshly isolated and cultured chick osteoclasts / Adam F. Weidema, Jan H. Ravesloot, György Panyi, Peter J. Nijweide, Dirk L. Ypey
Dátum:	1993
ISSN:	0005-2736
Megjegyzések:	Calcium-activated potassium channels were found in embryonic chick osteoclasts using the patch-clamp technique. The activity of the channel was increased by both membrane depolarisation and an increase in intracellular Ca2+ concentration in the range 10(-5) to 10(-3) M. In the cell-attached-patch configuration the channel was only active at extreme depolarising potentials. Ca2+ addition to the cytoplasm via ionomycin increased channel activity at the resting membrane potential of the osteoclast. The channel had a single-channel conductance of 150 pS in the inside-out patch under symmetrical K+ conditions (150 mM) and was selective for potassium ions. During sustained application of increased [Ca2+] at the cytoplasmic side of inside-out patches, channel activity sometimes decreased again after the initial increases (desensitization). The results established the properties of the single channels underlying an outward rectifying K+ conductance in chick osteoclasts described previously by us.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Potassium ion channel Calcium ion dependence Patch clamp Depolarization Calcium ion concentration, intracellular Chick osteoclast
Megjelenés:	Biochimica et Biophysica Acta (BBA). Biomembranes. - 1149 : 1 (1993), p. 63-72. -
További szerzők:	Ravesloot, Jan Hindrik (1961-) Panyi György (1966-) (biofizikus) Nijweide, Peter J. Ypey, Dirk L.
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI Szerző által megadott URL
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