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Modification of K+ conductance of heart cell membrane by BRL 34915

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Summary

1. The effect of the K+ channel agonist BRL 34915 on membrane conductance was investigated in isolated guinea-pig cardiac myocytes. 2. BRL 34915 reduced the duration of the transmembrane action potential and slightly increased the membrane resting potential in a concentration-dependent manner. 3. BRL 34915 removed the rectification in the steady-state current-voltage relationship. At membrane potentials more negative than the K+ equilibrium potential, membrane conductance was reduced. In the presence of 10−4 mol/l BRL 34915, the current-voltage relationship was linear, i.e. of an ohmic type. 4. The BRL 34915-mediated change in membrane conductance was susceptible to the K+ channel blockers BaCl2 and tetrahydroaminoacridine. 5. In conclusion, BRL 34915 modifies K+ conductance in the cardiac cell membrane. The precise nature of the K+ conductance change remains to be elucidated.

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  1. Pharmaceutical Research Department, F. Hoffmann-La Roche & Co., Ltd., CH-4002, Basel, Switzerland

    Wolfgang Osterrieder

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  1. Wolfgang Osterrieder
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Osterrieder, W. Modification of K+ conductance of heart cell membrane by BRL 34915. Naunyn-Schmiedeberg's Arch Pharmacol 337, 93–97 (1988). https://doi.org/10.1007/BF00169483

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  • DOI: https://doi.org/10.1007/BF00169483

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