Cation movements in perfused giant axons

Abstract

The net movements of Na and K into resting squid giant axons perfused with a K2SO4 artificial axoplasm have been determined. Na enters at a rate of 131 [plus or minus] 25 p-mole/cm2.sec. The K leakage from the fiber is 942 [plus or minus] 566 p-mole/cm2. sec; clearly this latter figure shows how large is the uncertainty in the exact value for the potassium leakage. The net entry of sodium associated with activity in such fibers has been measured and is 5.7 [plus or minus] 0.7 p-mole/cm2. impulse.