Lysis of Dog Erythrocytes in Mildly Alkaline Isotonic Media

¹ From the Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

Dog erythrocytes undergo hemolysis in any isotonic medium with a value of ph higher than 7.6. The higher the value of ph, the more rapidly and the more completely hemolysis occurs; at ph 7.6 about 2 hours are required for noticeable hemolysis either in vivo or in vitro. This phenomenon does not occur with the erythrocytes of man, cat, mouse, guinea pig, rabbit, sheep, horse or ox. The erythrocytes of all species studied were seen to approach a spherical shape as the ph was increased above 7.5 and to become crenated at ph values below 7.3. The transition to a spherical shape in alkaline media is not due to an increase in volume but rather to a contraction of the surface membrane. It is suggested that the dog erythrocyte differs from that of other species in that its membrane can withstand less tension.