Cytogenetic effects of quinoxaline-1,4-dioxide-type growth-promoting agents. II. Metaphase analysis in mice.

The clastogenicity of the growth-promoting agents, carbadox, olaquindox and cyadox, was examined by the metaphase analysis of chromosome aberrations in bone marrow of mice. The agents were administered by a stomach tube to male ICR mice 24 h before they were killed. Single-dose levels were 50, 100 and 200 mg/kg for carbadox; 200, 400, 600 and 800 mg/kg for olaquindox; and 400, 800 and 1200 mg/kg for cyadox. Carbadox was the most active; it induced chromosome aberrations even at a dose of 100 mg/kg. Olaquindox had about the same activity at a dose of 800 mg/kg. No chromosome-damaging effect of cyadox was observed even at a dose of 1200 mg/kg.