Cytochalasin B I. Effect on Cytokinesis of Novikoff Hepatoma Cells 1

Abstract

Summary

The mold metabolite Cytochalasin B (CB inhibits cytoplasmic division (cytokinesis) while allowing nuclear division to proceed. N1S1-67 (Novikoff rat hepatoma) cells exposed to drug concentrations of 2.1 × 10^-6 M do not undergo cytoplasmic division, but cell volume and number of nuclei per cell increase at rates which are comparable to the rates of similar processes in controls. Incorporation of ³HTdr, ³HUdr, ³H-L-leucine and ³H choline suggest that such increases represent true nuclear and cytoplasmic growth.

These results indicate that inhibition of macromolecular synthesis does not account for the action of CB. The inhibition of a process of membrane fusion is suggested as a possible mode of action of the drug.