Visible chemiluminescence from rat brain homogenates undergoing autoxidation. I. Effect of additives and products accumulation.

Rat brain homogenate autoxidation was assessed from thiobarbituric acid reactant accumulation (TBAR), light emission, and oxygen uptake. The effect of several additives upon TBAR accumulation and light intensity suggests that these parameters can be employed as a reliable measure of the lipoperoxidation extent. From the different time profiles of TBAR accumulation and light emission, it is concluded that instantaneous light emission is not a measure of the lipoperoxidation rate but it is related to the accumulation of products. The time dependence of the light emitted after addition to an incubated sample of an excess of free radical scavengers indicates that at least two intermediates of widely different lifetimes are contributing to the observed light emission.