Electrical activation of Na/K pumps can increase ionic concentration gradient and membrane resting potential.
It has been previously demonstrated by our group that our specifically designed synchronization modulation electric field can dynamically entrain the Na/K ATPase molecules, effectively accelerating the pumping action of these molecules. The ATPase molecules are first synchronized by the field, and subsequently their pumping rates are gradually modulated in a stepwise pattern to progressively higher and higher levels. Here, we present results obtained on application of the field to intact twitch skeletal muscle fibers. The ionic concentration gradient across the cell membrane was monitored, with the membrane potential extrapolated using a slow fluorescent probe with a confocal microimaging technique. The applied synchronization-modulation electric field is able to slowly but consistently increase the ionic concentration gradient across the membrane and, hence, hyperpolarize the membrane potential. All of these results were fully eliminated if ouabain was applied to the bathing solution, indicating a correlation with the action of the Na/K pump molecules. These results in combination with our previous results into the entrainment of the pump molecules show that the synchronization-modulation electric field-induced activation of the Na/K pump functions can effectively increase the ionic concentration gradient and the membrane potential.
Chen
Wei
W
Department of Cellular and Molecular Biophysics, University of South Florida, Tampa, Florida 33620, USA. wchen@cas.usf.edu
Dando
Robin
R
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000737:chemistry; D017136:Ion Transport / Q000187:drug effects / Q000502:physiology; D007477:Ions / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D018613:Microscopy, Confocal; D010042:Ouabain / Q000494:pharmacology; D011894:Rana pipiens; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007477:Ions; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase