| Autor: |
Cruz Jdos S; Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan., Matsuda H |
| Jazyk: |
angličtina |
| Zdroj: |
European journal of pharmacology [Eur J Pharmacol] 1994 Feb 15; Vol. 266 (3), pp. 317-25. |
| DOI: |
10.1016/0922-4106(94)90142-2 |
| Abstrakt: |
The effects of a bufadienolide isolated from toad venom, arenobufagin, a potent Na+/K+ pump inhibitor, were studied in single guinea-pig ventricular cells in the whole-cell patch-clamp configuration. Arenobufagin (50 microM) applied extracellularly decreased the amplitude of the delayed rectifier K+ current (IdK) by 30% without affecting the gating kinetics. The L-type Ca2+ current was also depressed, but to a lesser extent. The inward rectifier K+ current was hardly affected. Ouabain and the internal dialysis of cells with the solution containing 20 mM Na+ depressed IdK in a similar way as arenobufagin. On the other hand, arenobufagin also depressed IdK when the Na+/K+ pump was already inhibited in the K(+)-free Tyrode solution. Therefore, both a direct effect on the channel and an indirect effect through the inhibition of the Na+/K+ pump may be involved in the depression of IdK by arenobufagin. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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