Effects of Some Inhibitors on the Temperature-Dependent Component of Resting Potential in Lobster Axon

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Abstract
The resting membrane potential of the lobster axon becomes 5-8 mv more negative when the temperature of the perfusion solution is increased 10[degree]C. This potential change is about twice that predicted if the axon membrane potential followed that expected for a potassium ion electrode potential. When the inhibitors, 2,4-dinitrophenol, sodium cyanide, and sodium azide, were added separately to the perfusion medium the potential change was reduced to about 1.4 times that predicted for a potassium ion electrode potential. Assays of axons exposed to these inhibitors showed that ATP levels were reduced to about one-fourth that obtained for control axons. Ouabain added to the perfusion medium reduced the potential change to that expected for a potassium ion electrode potential. These results suggest that the resting potential changes with temperature as a result of the activity of an electrogenic ion pump.