Abstract
Lipid peroxides, which are mainly hydroperoxides, contained in 1mL of human serum could be determined accurately under ice-cooled condition by potentiometry used with an automatic titrator.
The average values per 1 mL of sera of 105 healthy males in their twenties were 25.3±14.3 neq for peroxides and 2.32 ± 0.86 nmol for TBA, respectively. TBA values for various sera showed the equivalent of only ca. 20% on the average for peroxide content determined by potent-iometry. However, there was no relationship between potentiometric peroxide levels and colorimetric TBA values due to the large coefficient of variation in detection ratio of peroxides by TBA method, where the ratio was calculated as x mol peroxides for TBA divided by y mol peroxides obtained from the potentiometry, i, e., x/y.
Also is discussed the influence of the levels of iron compounds or polyunsaturated fatty acids (PUFA), which are the constituents of lipids, present in various sera samples upon the lipid peroxide content, TBA values or detection ratios of peroxides by TBA method.
Iron compounds in serum were found to have no catalytic effect on the accumulation of lipid peroxides in vivo and TBA measurements since their amounts were so small. The levels of lipid peroxides were independent of PUFA content but the detection ratios of peroxides by TBA method depended on the content in each serum sample.
