The effect of Rb+, Cs+, and T1+ on the gramicidin A-induced conductance changes of the skeletal muscle cell membrane.
The channel-forming antibiotic gramicidin A increases the K+ conductance of frog skeletal muscle fibres in isotonic K2SO4 solution. The conductance of the gramicidin channel is not affected by Rb+ or Cs+, but is reduced by T1+. In contrast, the conductance of the normal K+ channel is decreased by Rb+ and Cs+ but is nearly unaffected by 5 and 10 mM T1+. The results suggest differences in the cation permeation through the gramicidin and the K+ channel of the muscle cell membrane.
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002586:Cesium / Q000494:pharmacology*; D006096:Gramicidin / Q000494:pharmacology*; D007473:Ion Channels; D009132:Muscles / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011893:Rana esculenta; D012413:Rubidium / Q000494:pharmacology*; D013793:Thallium / Q000494:pharmacology*
D007473:Ion Channels; D006096:Gramicidin; D002586:Cesium; D013793:Thallium; D012413:Rubidium