RHEOLOGICAL BEHAVIOR OF LEUKOCYTES.

The rheological behavior of white blood cells is important to their passage through the microcirculation and to their egress into surrounding tissue in inflammation or infection. White blood cells exhibit a passive viscoelastic behavior and are also capable of active motion and migration when exposed to a chemotactic agent. In the present paper, a phase of the passive response is treated which simulates the behavior of the cell as a whole, rather than only a small portion. The particular phase modelled here is the recovery of a leukocyte to a spherical shape after deformation to a sausage shape by aspiration into a pipette. After expulsion from the pipette, the cell deformation is recorded on video-tape and the major and minor diameters are measured later. The cells were suspended in a medium that prevented active motion.