Studies on the sequestration of chemically and enzymatically modified erythrocytes

We have developed an experimental animal model to establish the patterns of sequestration of untreated, as well as chemically and enzymatically modified red blood cells (RBC). The intraperitoneal route of transfusion provides a useful way of transferring large numbers of untreated RBC into small animals and assuring their introduction into the circulation within 24 hr. Moreover, this route "filters" some types of modified erythrocytes, eg, glutaraldehyde treated RBC. From the pattern of sequestration, the RBC in the peritoneal cavity then pass through the liver where other types of modified RBC are sequestered, eg, after trypsin, pronase, protease, or sialidase treatment. Some modified RBC show a preference for the spleen as the site of sequestration, eg, galactose oxidase or N-ethylmaleimide treated RBC. These appear in the spleen despite intraperitoneal transfusion. Relevant to this study is the observation that in the rat old RBC are sequestered both by liver and spleen, while asialoerythrocytes are sequestered by liver only. A possible reason for this difference is discussed in the text.