MICRONUCLEATED CELLS DURING THE GROWTH OF THE EHRLICH ASCITES TUMOR ON SPONTANEOUS AND BY TITANOCENEDICHLORIDE-INDUCED CONDITIONS

The micronucleus assay was used to investigate the activity of the Ehr lich-ascites tumour (EAT) of mice to produce chromosomal abet-rations under spontaneous and chemically induced conditions. Titanocene dichlo ride (TDC), a cytostatic drug similar to cis-platinum, was injected in several dosages into the peritoneal cavity of mice carrying the tumou r (40, 60 or 80 mg/kg). Our results show that there exists a constant spontaneous level of micronucleated cells (MNC), and that TDC is a pot ential dose-related inductor of micronuclei (MN). The highest amounts of MN are registered 48 h after application. We discuss the results in context with basic cytokinetic data of our tumour. This leads to the postulation of a dynamic balance of generating and eliminating factors producing the actual level of MNC.