ANTIPROLIFERATION ACTIVITY AND THE MECHANISM OF ACTION OF 9-BROMO-5-MORPHOLINO-TETRAZOLO[1,5-C]QUINAZOLINE - POTENTIONAL ANTICANCER DRUG

9-Bromo-5-morpholino-tetrazolo[1,5-c]quinazoline (BMTQ) at the two hig hest tested concentrations (74.6; 29.8 mu mol//1) induced retarded cyt otoxic effect. After 24 hours of culturing 23.1-98.8% of the cell popu lation proliferated but after 48 and 72 hours 6.4-80.4% of the cell po pulation degenerated. Other concentrations induced toxicity that was c oncentration- and time-dependent. The cytolytic concentrations of BMTQ induced integrity damage of cytoplasmatic membrane. The inhibition of cell cycle and the elevated content of proteins in the cell exposed t o the cytotoxic concentrations of BMTQ suggest that the cells synthesi ze protein without entering into mitosis and that dying cells are in t he S-phase before death. BMTQ induced 1.75-3.01-times increase of the level of ssDNA in comparison with the control.