Abstract

1. By the method of osmotic hemolysis an attempt has been made to evaluate the indirect osmotic effects upon mammalian erythrocytes of changes in the pH, temperature, and oxygen tension of the surrounding medium. 2. The observed effects of these three factors, within the range considered, are of the order of magnitude of those predicted by the equation: [See equation in the PDF file] where W1 and W2 are the amounts of water contained in an erythrocyte under two given conditions, F1 and F2 are the amounts of base bound by one equivalent of hemoglobin under the same conditions, C1 and C2 are the concentrations of the solutions in question and R is the ratio of base to hemoglobin within the cell. It is probable that the effects of the factors studied are primarily osmotic in nature, though smaller effects of a different sort are by no means excluded. 3. Certain differences between the osmotic behavior of the erythrocyte and that of other cells are discussed. 4. It is shown that pH changes of as little as 0.01 pH unit and temperature changes of as little as 0.5° C. may have a measurable effect upon the observed degree of hemolysis. It follows, therefore, that "fragility" tests and other osmotic studies upon erythrocytes in which these factors are not properly controlled are of little value.