Motility of human polymorphonuclear leukocytes. Roles of hydroxy fatty acids, other lipids, and cations.

Rapid ionic fluxes across local areas of leukocyte plasma membranes result in local swelling, ie, ruffling or blebbing. These fluxes are stimulated either locally or generally over the cell membranes by hydrophobic chemotactic peptides. This swelling is associated with migration of the cells in the direction of the swollen area of the cell. Hydroxy fatty acids, other lipids, and Ca++ ionophores activate a Ca++-dependent migratory activity of the cell, whereas acidic peptides activate a monovalent cation-dependent migratory activity. These two processes are therefore additive. The swelling due to the peptides results in an increase in urea space but no change in inulin space, whereas, swelling due to permeant cations and anions causes a massive increase in both spaces. Migration appears to result from the pushing of cellular contents, nucleus and cytoplasm, into the more swollen area of the cell by unopposed contraction of the unswollen area of the cell.