Enhancement of chemotactic migration by the local anesthetic tetracaine.

The local amine anesthetic tetracaine added to a suspension of guinea pig or human neutrophilic granulocytes inhibited their random migration in Boyden chambers, but increased their chemotactic migration towards the chemotactic tripeptide f-Met-Leu-Phe, complement-activated normal guinea pig serum, and the eosinophil chemotactic factor ECF. Tetracaine not only increased the distance migrated by the leading cells, it also caused more cells to leave the upper filter surface and to migrate into the filter. The effect required the presence of the drug; cells preincubated with tetracaine and washed did not differ from control cells. It is suggested that tetracaine specifically enhanced a mechanism operative in a cell's response to a concentration gradient of a chemotactic factor.