[The patterns of colchicine-induced death of lymphoid cells]

It is shown that colchicine injection at doses higher than 1 mg/kg of animal weight induces cell death in thymus, spleen, bone marrow and intestine mucosa. The cell death is accompanied by a regular internucleosomal cleavage of nuclear DNA and by the elimination of the formed fragments from cells. Both the processes begin after a 1.5 hour lag-period and proceed before the outer membrane permeability for supravital dyes increases. DNA degradation is prevented by the inhibitor of protein synthesis cycloheximide. Cytochalasin B does not induce chromatin degradation or cell death and has no effect on radiation death of lymphocytes. A possible role of microtubule destruction as a switch-on mechanism of DNA degradation and cell death is discussed.