Abstract: | The physiologically active metal ions with fixed valence Ca2+ and Mg2+ were shown to accelerate epinephrine autoxidation at an alkaline pH, which proceeds via the known quinoid pathway and is accompanied by the generation of reactive oxygen species. A higher efficiency was observed for Ca2+ ions compared with Mg2+ ions. The activation of epinephrine autoxidation was evident from a decrease in the time of the initiation of the chain reaction to begin (i.e., the reaction lag) and an increase in the rate of both oxygen uptake and the formation of adrenochrome. Based on the observed effects, Ca2+ and Mg2+ cations were assumed to have the potential to play a role in the free radical processes that are associated with redox reactions in the cell and can also modulate the effect of epinephrine in the organism its oxidation via the quinoid pathway. |