Interactions of the anti-tumor ametantrone and mitoxantrone with rat hepatic microsomes

The interaction of the anti-tumor anthraquinones, ametantrone and mitoxantrone, with rat hepatic microsomes has been studied with a fluorescence technique using 7,12-dimethylbenzanthracene as a new fluorescent probe. The two drugs were able to quench the intrinsic fluorescence of microsomal suspension. Mitoxantrone was able to displace dimethylbenzanthracene bound microsomes with a linear representation of one ligand-one acceptor model, whereas bimodal shape was found in the case of ametantrone. The mechanism of quenching and/or binding is discussed.