Indifference of the resting potential of frog muscle cells to external Mg++ in the face of high Mg++ permeability.
Incubation of frog sartorius muscles for 18 hours at constant external concentrations of K+ and Na+, but with the external concentration of Mg++ varying from 1.2 to 73.2 mM, brought about no change in the resting potential which remained constant at 88 mV. Results were the same in MgCl2 as in MgSO4. However, these cells are nearly as permeable to Mg++ as they are to K+. These results contradict the membrane theory of the cellular potential but are compatible with the surface adsorption model of the cellular potential.
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002463:Cell Membrane Permeability / Q000187:drug effects; D008274:Magnesium / Q000378:metabolism* / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D008954:Models, Biological; D009132:Muscles / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D011894:Rana pipiens; D012964:Sodium / Q000494:pharmacology
D012964:Sodium; D008274:Magnesium; D011188:Potassium