[Reversible suppression of cellular aggregation by cytochalasin B and kolkhamin]

Aggregation of normal mouse fibroblast-like cells plated on the surface of millipore filter was studied quantitatively. It was shown that addition of 10 mug/ml of cytochalasin B (a drug which blocked active cell locomotion) or 0.1 mug/ml of colcemid (a drug which destroyed polarization processes in the cells and therefore interfered with the oriented cell movement) completely inhibited such aggregation. This inhibition was reversible: after the drugs were washed off the cells did aggregate. It was concluded that cell aggregation in this experimental system required active cell movement and cell polarization.