Studies on the Determination of Serum Lipoperoxides by Thiobarbituric Acid Reaction.(Fluorometric Assay)

Abstract

Some problems on the determination of lipoperoxides in serum by TBA reaction were described. Reproducibility on this method with 10 samples was good, as CV=3.4%. The relationship between 1, 1, 3, 3 TEP cocentration and fluorescence at 553 nm (Em) was linear up to at least n mole of TEP.
However, in serum sample, it was linear up to a serum volume of 50μl. Deproteinization on this method was almost complete. To rinse the precipitant, water and 1/12 N H₂SO₄ were suitable and one rinse was enough.
0.34% TBA in 50% acetic acid showed maximum fluorescence on TBA reaction. On the timecourse of TBA reaction, 1, 1, 3, 3 TEP and serum showed different response. Stability of lipoperoxides in serum did not change up to 6 days at 4°.
New peak by bilirubin was found at the wavelength 580 nm (Em) after TBA reaction. We found the same peak by Bilirubin Control as serum. As the wavelengthis very closed to 553 nm, fluorescence spectra should be checked when the bilirubin level in serum is high.
Lipoperoxides values and GOT, GPT, Al-P, γ-GTP, cholesterol, Triglycerides values in various sera were determined. In sera of hyperlipidemia, high lipoperoxides levels were observed though their enzyme levels were low. Significant correlation was observed between lipoperoxides values and cholesterol values (n=50, r=0.83) than that of TG.