Blood clam (Anadara inflata) red cells. Partition in aqueous two-polymer phase systems.

Abstract

Abstract Anadara inflata is a clam which has red blood cells in its hemolymph. Furthermore, the nucleated red blood cells contain two structurally distinct hemoglobins. Clam red cells were subjected to partition in aqueous dextran-polyethylene glycol two-phase systems with the following results: 1. 1. Clam red cells are the largest cells (about 20 μm in diameter) so far studied in two-polymer phases. It is shown that not only can such cells be partitioned in dextran-polyethylene glycol phase systems, but that countercurrent distribution resolves the clam red cell population into more and less metabolically active cells. The distribution of these cells in relation to the whole population is similar to that of young and old red cells from mammals. 2. 2. The high tonicity of clam red cells enabled us to study the partition behavior of cells (under isotonic conditions) at much higher salt or salt plus sucrose concentrations than heretofore possible with mammalian erythrocytes. A number of parameters were studied. The most interesting results are the analogies in partition behavior of clam red cells to that of proteins when teh NaCl concentration is increased (0.1–0.5 M); and to that of mammalian red cells with increasing phosphate buffer/NaCl concentrations (total salt about 300 mosM). 3. 3. While we can not state whether the two hemoglobins of this clam are contained in the same or in different red cells, it can be concluded that if the two hemoglobins are in different cells these must have similar surface characteristics.