Fluorometric Determination 1 , 3 - biphenyl - 2 - thiobarbituric of Lipid Acid Peroxides in Tissues with

Lipid peroxides in tissues were fluorometrically determined using 1,3-diphenyl-2-thiobarbituric acid (DPTBA) as a fluorogenic reagent, and the results were compared with those obtained by the DPTBA-visible method, thiobarbituric acid (TBA)-fluorescence method, or TBA-visible method. The optimum conditions for determining lipid peroxides were analyzed by using brain homogenate. The optimum pH for the reaction of brain homogenate with DPTBA was 2.5. The amount of DPTBA suitable for the reaction with 100 μl of a 1 % brain homogenate was 0.12 M. A linear relationship was observed between the fluorescence intensity and the amount of malondialdehyde (MDA) in the range of 1.25-12.5 nmol/ml. The detection limit of the DPTBA-fluorescence method was 0.006 nmol/g wet weight at a signal-to-noise ratio of 3. The sensitivity of this method was 5.5 times higher than that of the TBA-fluorescence method, lipid peroxides in tissues could be easily determined without separation from