The effect of tocopherol and dimethyl sulfoxide on focal edema and lipid peroxidation induced by isocortical injection of ferrous chloride.

Addition of iron salts to suspensions of subcellular organelles or polyunsaturated fatty acids results in the formation of oxidative free radicals with subsequent initiation of lipid peroxidation. Pretreatment of rats with anti-oxidants prevents peroxidation following isocortical ferrous chloride injection, and increases the rate of resolution of iron-induced focal edema. In this experiment, treatment of rats at the time of injection of 5 microliters of 100 mM FeCl2 with tocopherol and DMSO caused decreased formation of brain peroxidation at the injection site, as measured by formation of MDA. Tocopherol failed to change the quantity of tissue fluid accumulation. However, DMSO alone, or combined with tocopherol, hastened the resolution of brain edema. Tocopherol may terminate peroxidation reactions by donation of a phenolic hydrogen, forming a quinone of tocopherol. DMSO has many pharmacologic effects; however, inhibition of initiation reactions by scavenging hydroxyl radicals, and direct and indirect effects on focal edema accumulation may account for our observations.