COMPARATIVE TOXICITY OF ALKYL-1,4-NAPHTHOQUINONES IN RATS - RELATIONSHIP TO FREE-RADICAL PRODUCTION IN-VITRO

2-Methyl-1,4-naphthoquinone causes haemolysis in vivo. This toxic effe ct is believed to result from oxidative damage to erythrocytes by ''ac tive oxygen'' species formed via one-electron reduction of the naphtho quinone by oxyhaemoglobin. In the present investigation, seven 2-alkyl -1,4-naphthoquinones have been studied with regard to their haemolytic activity in rats, their ability to cause oxidative damage in erythroc ytes in vitro, and their reactivity toward oxyhaemoglobin. A close cor relation was observed between the in vivo and in vitro parameters, sug gesting that the proposed mechanism of toxicity of 2-methyl-1,4-naphth oquinone is correct and is also applicable to other allkylnaphthoquino nes.