Iron-catalyzed free radical reactions, such as the peroxidation of membrane lipids or the inactivation of critical enzymes, have been implicated in the cardiotoxicity of Adriamycin. Fe3+ reduction is an important step in both processes. The reduction of Fe3+, Fe3+ ADP, or Fe3+-ferritin by rabbit heart microsomes, Adriamycin, and NADPH was 10% inhibited by ICRF-187 (ADR-529) in N2 and 77% inhibited by ICRF-198, the hydrolysis product of ICRF-159 (the racemic form of ICRF-187). Lipid peroxidation and CaATPase inactivation catalyzed by Fe3+, Fe3+ADP, or Fe3+-ferritin were substantially inhibited by ICRF-198 but only partially inhibited by ICRF-187. The cardioprotective action of ICRF-187 during Adriamycin treatment may be a result of its hydrolysis to the d isomer of ICRF-198 which inhibits reduction of Fe3+, thus limiting the role of iron in tissue damaging free radical reactions.


This work was supported by the Cancer Society of New Zealand and the Medical Research Council of New Zealand.

This content is only available via PDF.