| Autor: |
Häussler, U., Rivet-Bastide, M., Fahlke, Ch., Müller, D., Zachar, E., Rüdel, R. |
| Zdroj: |
Pflügers Archiv: European Journal of Physiology; 1994, Vol. 428 Issue 3/4, p323-330, 8p |
| Abstrakt: |
The effects of volume change and cytoskeleton manipulation on the Cl channels in human embryonic skeletal muscle cells were studied. Trypsination, used for production of myoballs, changes the channel properties only a little. When the external osmolarity was reduced from 300 to 270 mosmol/l, the specific Cl conductance, g, (at &-80 mV) of myoballs increased from 5.1±1.9 to 30.4±12.2 μS/cm (SD; n=6) within 15 min. Concomitantly, the kinetics of Cl currents, elicited by clamping the membrane potential from a negative to positive values, changed from activation and subsequent slow inactivation to instantaneous activation with fast inactivation. G protein activation, protein kinase action or [Ca] elevation seemed not to be involved in these effects. Similar changes were produced in the absence of a transmembrane osmotic gradient by 500 nM intracellular cytochalasin D ( g=34.3 ±10.3 μS/cm; n=6) or 12.5 μM colchicine ( g= 15.4±1.4 μS/cm; n=5). When the external osmolarity was increased to 418 mosmol/l, 1 μM cytochalasin D did not affect g. In four of six cell-attached patches the open probability of the intermediate Cl channel was increased after reduction of the bath osmolarity. In inside-out patches, the drugs increased the open probability of the channels. It is concluded that the Cl channels are under control of the cytoskeleton. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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