Abstract
The effect of various cations on the action current of frog's skin was investigated. Solutions to be tested were applied to the inner surface of skin. The stimulus used was a single maximum induction shock.
1. The magnitude of the action current is usually decreased when Ringer is substituted for Ringer containing a great amount of alkalimetal-and alkali earth metal ions. The order of reducing effects of ions follows Hofineister's lyotropic series:
K.>NH.4>Li.>Na..
The series for alkali earth metal ions is as follows:
Al ...>Ba..>Mg..>Ca...
2. Ca.. increases the action current above normal in adequate con-centration.
3. Antagonistic action can be demonstrated not only between K. and bivalent cations such as Ca.. and Mg.. but also between two kinds of monovalent cations such as K. and Li..
4. The action current is scarcely affected by changing pH of the medium from 4.3 to 8.2.
