Lipoid Solubility, Permeability and Hemolytic Action of the Saturated Fatty Acids.*

Hemolysis by fatty acids is closely related to the ability of these substances to penetrate the red blood cell membrane. Jacobs (1) has studied hemolysis produced by ammonium salts of the fatty acids and found that these owe their hemolytic effect to the permeability of the corpuscle to ammonia and the fatty acids, both entering the cell with relative ease even in the undissociated form. The accumulation of ammonium salts of the fatty acids inside the corpuscle leads to the osmotic effects which ultimately result in the disintegration of the cell. The penetration of fatty acids into living tissues has been the subject of many excellent investigations (Loeb, Harvey, Crozier, Taylor, and others), but with the exception of the work of Jacobs with the ammonium salts and the essentiahy qualitative study of Fiihner and Neubauer (2), the permeability of the erythrocyte to fatty acids and the hemolytic action of these substances have received little attention. Loeb (3) studied the effect of different acids in the formation of artificial fertilization membranes in sea urchin eggs and found the order of effectiveness to be as follows: formic <acetic < propionic < butyric < caprylic < nonylic. Harvey (4) investigated the penetrat,ion rates of different acids into the testis of the “prickly fish,” which contains a purple watersoluble pigment sensitive to acids, and found that valeric acid penetrated much more rapidly than any of its lower homologues. Croder (5) measured the penetration rates of various acids into