Changes in ionic movements across rabbit polymorphonuclear leukocyte membranes during lysosomal enzyme release. Possible ionic basis for lysosomal enzyme release.

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Abstract
In the presence of cytochalasin B, the chemotactic factor formyl methionyl leucyl phenylalanine (FMLP) induces within 30 s large enhancements in the influxes of both 22Na+ and 45Ca+2 and an increase in the cellular pool of exchangeable Ca. The magnitude of the changes induced by cytochalasin B and FMLP exceeds that induced by FMLP or cytochalasin B alone, and cannot be explained on the basis of an additive effect of the 2 agents. These compounds either separately or together produce much smaller enhancements in 45Ca efflux. The divalent cation ionophore A23187 also produces a rapid and large increase in the influxes of both 22Na and 45Ca+2 in the presence and absence of cytochalasin B. An excellent correlation was found between Ca influx and lysosomal enzyme release. 42K influx is not significantly affected by any of these compounds. A large and rapid increase of 42K efflux is observed under conditions which give rise to lysosomal enzyme release. A flow diagram of the events that are thought to accompany the stimulation of polymorphonuclear leukocytes by chemotactic or degranulating stimuli is presented.