Latrunculin A is a potent inducer of aggregation of polymorphonuclear leukocytes

We have shown that latrunculin A, a toxin from a Red Sea sponge which has striking effects in several phenomena dependent on the cytoskeleton, is a potent inducer of aggregation of rabbit polymorphonuclear leukocytes in a dose- and time-dependent manner. From 12 nM to 60 nM toxin the degree of aggregation (after 8 min) in nearly directly proportional to the toxin concentration; the aggregation effect is energy-dependent from the glycolytic pathway. It was also shown that 120 nM latrunculin A, after 5 min incubation, can reduce to more than half the F-actin percent of the leucocytes. These results may contribute to the study of the relations between the actin cytoskeleton of leukocytes and the process of aggregation which is involved in important physiological functions of these cells.