[Indices of oxidative stress. 1. TBA-reactive substances and carbonylproteins]

The method of measurement of two oxidative stress indices, TBA-reactive substances and carbonylproteins, in one sample has been proposed using different tissues of common carp. Optimal time of boiling of the preparations with thiobarbituric acid was 60 min. Protein has been solubilized in 6 M guanidine-HCl, or 6 M urea, or 5% sodium dodecylsulphate solutions. Carbonylprotein concentration has been proposed to measure in guanidine-HCl solution and to calculated per protein content in these solutions. The concentration of carbonylproteins rose during incubation of carp kidney preparations with ascorbic acid (0.1-0.5 mM) and ferrous sulphate (2.5-20.0 microM). Incubation of kidney preparations with 0.5 mM ascorbic acid and 20 mM ferrous sulphate showed that the carbonylprotein content has been elevated starting with 60 min incubation and reached 8-fold increase during 120 min. Methodological aspects of oxidative stress indices measuring are discussed.