STUDIES ON THE OSMOTIC FRAGILITY OF INCUBATED NORMAL AND ABNORMAL ERYTHROCYTES*

Abstract

Normal and ab-normal erythrocytes, during aseptic incubation at 37[degree]C in their own serum over a period of 72 hours, underwent a three-phase, cyclic change in osmotic fragility. Normally, the first phase, characterized by increasing osmotic fragility, occurred during the first 24 hours; the second phase, in which fragility decreased, occurred in the next 24 hours; the third phase, a return to increasing fragility, followed in the next 24-hour period. The amplitude of the cyclic change depended upon the tonicity in which the osmotic fragility was determined. Abnormal erythrocytes exhibited changes in the period of the cycle, the amplitude of the cycle, or the tonicity at which maximum amplitude was observed. The addition of glucose or adenosine to the incubation serum delayed the onset of the second phase; fluoride abolished the first phase and advanced the occurrence of the second phase. Postulated mechanisms for these changes were discussed.