The role of spleen in suppressing the rheological alterations in circulating blood.

The role of spleen in maintaining the normal rheological properties of red blood cells (RBC) has been investigated by comparing the time course of RBC deformability assessed by the cell transit analyzer (CTA), after the induction of RBC mechanical alterations, in splenectomized and normal guinea pigs. After the exchange transfusions with glutaraldehyde treated (hardened) RBC, most of these cells were removed from the circulation in the splenectomized animals as well as the animals with intact spleens. However, the CTA could detect the longer existence of a small population of hardened RBC in circulation in the splenectomized animals. Measurement of RBC transit times after the onset of experimental sepsis (cecal ligature-puncture) revealed that, in the splenectomized guinea pigs RBC deformability impairment started earlier, in comparison with the animals with intact spleens. These results suggest that the spleen plays an important role in maintaining the normal rheological properties of the circulating blood, especially in the presence of pathophysiological processes affecting RBC mechanics.