Hormone dependency of chromosome aberrations induced by 7,12-dimethylbenz[a]anthracene in rat bone marrow cells: site-specific increase by erythropoietin.

The frequency of chromosome aberrations (CA) 6 hours after iv injection of 50 mg 7,12-dimethylbenz[a]anthracene (DMBA)/kg was studied in bone marrow cells of the noninbred Long-Evans rat under various hematopoietic conditions. The percentage of metaphase cells with CA was enhanced by anemia and suppressed by polycythemia. The low incidence of CA in polycythemic rats was reversed by 6 U of sheep erythropoietin (EP) injected at the time of DMBA treatment. The interchromosomal and intrachromosomal distribution of CA indicated that hematopoietic stimuli, more specifically EP, greatly enhanced DMBA-induced CA in specific chromosomal regions.