Inhibition of iron-stimulated catecholamine degradation by the iron-chelators DETAFAC and Desferal: Potentially useful laboratory agents

The addition of ferrous sulfate to phosphate buffer at pH 7.4 brought about a large increase in the rate of autoxidation of dopamine or norepinephrine. The iron-chelating agents diethylenetri-aminepentaacetic acid (DETAPAC) and desferroxamine (Desferal) inhibited both the baseline as well as the iron-stimulated autoxidation of these catecholamines. Lesser inhibitory effects were observed with another iron-chelating agent, namely EDTA. In other experiments, DETAPAC or Desferal had little effect on the autoxidation of 6-hydroxydopamine in the absence of added ferrous sulfate, but both inhibited the ferrous sulfate-stimulated autoxidation. In contrast, both the baseline and ferrous sulfate-catalyzed rate of oxidation of 6-hydroxydopamine were greatly stimulated by EDTA addition. DETAPAC and Desferal appear to be useful experimental tools that may be added to solutions containing catecholamines to prevent their degradation.