IN VITROEFFECT OF COLCHICINE ON NEUTROPHIL GRANULOCYTE LOCOMOTION

The effect of colchicine on human neutrophil granulocyte chemotaxis, chemokinesis and spontaneous motility was examined, using a modified reversible Boyden chamber. Colchicine was shown to inhibit the attraction of neutrophils to casein and to a bacterial chemotactic factor at concentrations as low as 10(-7) M. Experiments in which the absolute concentrations and the concentration gradients of the chemotactic agent were varied, revealed that colchicine inhibited chemokinesis rather than chemotaxis. The spontaneous motility measured in the absence of chemotactic agents was not inhibited by colchicine. Pre-incubation of the cells with a bacterial chematactic factor did not change the sensitivity of the cells to colchicine. It is concluded that the integrity of microtubule function is not necessary for the ability of the cells to discern a concentration gradient or to react to this with directional locomotion. Thus the inhibitory effect of colchicine on neutrophil granulocyte chemokinesis may not depend on its inhibition of microtubule function. It is suggested that colchicine may block the still unidentified membrane mechanism involved in the translation of the recognition signal into an appropriate locomotory cell response.