CONCENTRATION OF LITHIUM, SODIUM AND POTASSIUM IN EPITHELIAL CELLS OF THE ISOLATED FROG SKIN DURING ACTIVE TRANSPORT OF LITHIUM.

The distribution of Li, K and Na in different layers of the skin of Rana temporaria was investigated after active transport of lithium. During the transport period the skin was short-circuited, and after it had been sectioned in the frozen state, the slices were weighed and analyzed for Li, K and Na It was found that: 1. The concentration of Li was higher in the epithelial cells than in the outside solution for outside lithium concentrations of less than 10–20 mmole/1. 2. This may be explained by assuming the inside of the epithelial cells negative with respect to the outside solution, and assuming the potential to be dependent on the outside concentration of lithium.