DNA binding of 4,4'-methylene-bis(2-chloroaniline) (MOCA) in explant cultures of human and dog bladder.

The binding to DNA of 4,4'-methylene-bis(2-chloroaniline) (MOCA) in explant cultures of human and dog bladder was compared. The DNA binding of MOCA in both human and dog bladder explants increased with the concentration of MOCA in the medium. In both species, there appeared to be a population with high DNA binding activity and another with low DNA binding activity. Furthermore, the binding of MOCA to human bladder DNA appeared to be higher than to dog bladder DNA. The results indicate the potential of MOCA to induce genetic damage in human bladder and suggest caution in the occupational exposure of humans to this chemical.