Cytochalasin B inhibits polyamine biosynthesis in HeLa cells.

Cytochalasin B (CB), a potent inhibitor of cytokinesis in mammalian cells, has been shown to cause the rapid inhibition of ornithine decarboxylase and S-adenosyl methionine decarboxylase activities followed by a gradual but marked decline in intracellular levels of both putrescine and spermidine. Further, the multinucleation induced by CB could be reversed to some extent by exogenous addition of polyamines to the growth medium. The results of this study suggested that polyamines might have some indirect role in the CB-induced multinucleation of mammalian cells.