Involvement of calmodulin in granulocyte chemotaxis: the effect of calmodulin inhibitors.

Chemotaxis and locomotion in rabbit peritoneal granulocytes are strongly inhibited by trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), both known as calmodulin inhibitors. This inhibition occurs in a concentration range where cell damage is not significant. Although inhibition was most pronounced in experiments with Ca2+ and Mg2+ present in the medium, inhibition of chemotaxis by trifluoperazine and W-7 was also observed in the absence of these ions. The results suggest that calmodulin is involved in granulocyte chemotaxis and locomotion.