Effect of colchicine on viscoelastic properties of neutrophils

The effect of colchicine (15-60 micrograms/ml) on the viscoelastic properties of human neutrophils was studied by the micropipette technique. The small deformation of the neutrophil in response to a step aspiration pressure was analyzed by using a three-element model in which an elastic element, K1, is in parallel with a Maxwell element composed of another elastic element, K2, in series with a viscous element, mu. Colchicine treatment of neutrophils caused decreases in K2 and mu without affecting K1. The results indicate that the integrity of the microtubules plays a significant role in providing the viscoelastic resistance (as represented by the Maxwell element in the model) of neutrophils to deforming stress.