may be significantP < 0.05
The Na gained by the cell in exchange for K may then be compared with the total loss of cellular K in order to determine whether a K-Na exchange can account quantitatively for the net K efflux. For 10.5 M ouabain the excess of K lost over Na calculated as gained in ex- change for K may be significant (P < 0.05, Student t-test); for 10.6 Mouabain the two quantities do not differ significantly, and the loss of cell K is reason- ably well accounted for by an exchange with Na.