The influence of L-sorbose on red cell flow properties, shape and packing ability

Since the sweet ketohexose L-sorbose causes overt hemolysis in dogs but not in man, we examined the possibility that L-sorbose induces a "prehemolytic state" of human red cells, manifesting itself as impairment of rheological red cell properties. After 2 hours incubation at 37 degrees C relative viscosity of red cell suspensions measured by radial spreading in filter paper and packing ability of red cells were normal. Incubation for 24 and 48 hours of red cells in media containing L-sorbose, glucose or no sugar showed that relative viscosity was best maintained in glucose. Relative viscosity and packing ability of red cells in L-sorbose containing suspensions decreased less than in suspensions without sugar. This difference was independent of the glucose metabolism, red cell ATP, osmolality and pH of the suspending media, but appeared to be related to different degrees of spheroechinocytic red cell shape transformation observed in different suspending media. It is possible that L-sorbose has some antiechinocytic properties and/or that it induces an alteration of red cell membrane flexibility. There is no indication of an L-sorbose induced "prehemolytic state" in human red cells.