OSMOTIC PROPERTIES OF THE ERYTHROCYTE

IV. IS THE PERMEABILITY OF HE ERYTHROCYTE TO WATER DECREASED BY NARCOTICS?

¹ From the Department of Physiology, University of Pennsylvania and the Marine Biological Laboratory, Woods Hole, Massachusetts

1. The observation of previous investigators that narcotic substances in proper concentrations tend to oppose osmotic hemolysis is confirmed in the case of several urethanes.

2. It is shown that the conclusion frequently drawn from such observations, that the antihemolytic effect of narcotics is due to a decreased permeability of the erythrocyte to water, is unwarranted by the existing experimental evidence. The necessity for a separation of "rate" and "equilibrium" factors in studies on osmotic hemolysis is emphasized.

3. It is shown by experiments in which these factors are properly separated that a slight but measurable retardation of osmotic hemolysis may be produced by low concentrations of urethanes. The possible nature of the mechanism of this retardation, which may perhaps in part involve a decreased permeability of the cell to water, is discussed.