Antagonistic Action of Anesthetics and Alkali Metal Ions on Permeability of Cell.

Abstract

Some years ago in experiments on pike eggs, I showed that there is an antagonism between the action of Na ions which increased the permeability of the plasma membrane and anesthetics which prevented the increase in permeability. Anesthetics in large doses, however, increased the permeability and killed the eggs. It was not shown that anesthetics ever decreased the normal permeability. At Woods Hole, Mass., I recently performed similar experiments on Fundulus eggs. Isotonic solutions of NaHCO₃ and of the nitrates of Ca and Na were made and mixed so as to reproduce the cations in about the same concentrations as in sea water. In this solution or in distilled water practically no chlorides diffused out of the eggs. A micronephelometer was made by painting black the sides of the plungers of a (B. & L.) microcolorimeter, removing the mirror and illuminating it with parallel, horizontal rays. Ten mg. of KCl in a litre of H₂O was taken as the standard. One cc. of the standard + 1 drop of 10% AgNO³ (acidified with HNO₃) was compared with 1 cc. of the unknown + 1 drop of AgNO₃ sol.∗ 100 eggs, washed until free from chlorides, were placed in 2 cc. of the solution. At the close of the experiment 1 cc. was removed for examination and the chloride content recorded in terms of the standard. Although sea water has a pH of about 8, the exosmosis of Cl was lowest at pH of 7 and less at pH 5 than at pH 8.

From experiments not given in detail it appears that Na⁺ and OH⁻ increase the permeability and Ca⁺⁺ and H⁺ inhibit their action. Alcohol has a similar effect to Ca⁺⁺.