Modulation of rabbit neutrophil chemotaxis by cytochalasin A. A comparison with other neutrophil functions.

Chemotaxis and stimulated locomotion by rabbit peritoneal neutrophils are inhibited by cytochalasin A; inhibition is complete with 5 X 10(-7) M cytochalasin A. Under the same conditions exocytosis and activation of the metabolic burst are stimulated maximally with 5 X 10(-7) M cytochalasin A. Inhibition of these function occurs at concentrations higher than 10(-6) M, inhibition being complete with 5 X 10(-6) M cytochalasin A. The sulfhydryl compound glutathione can prevent the inhibitory effect of cytochalasin A on chemotaxis. Inactivation of the sulfhydryl groups on the outer surface of the plasma membrane does not affect the inhibitory effect of cytochalasin A. It is concluded that the cellular target of cytochalasin A has a different significance for chemotaxis as compared with exocytosis and metabolic burst. The possibility that cytochalasin A reacts with sulfhydryl groups, located on a structure closely connected with the inner surface of the plasma membrane, is discussed.