The radical-producing activity of human platelets has been studied using the enhanced chemiluminescence method. It is shown that chemiluminescence of isolated platelets is observed only in the presence of lucigenin, a selective probe for superoxide anion; the luminescence is amplified many times upon the addition of NADH and NADPH, the substrates of oxidative chains. The chemiluminescence is not affected by diphenyliodonium, an inhibitor of NADPH oxidase, but it is inhibited in a dose-dependent manner by the oxidative phosphorylation uncouplers dinitrophenol and rotenone. Thus, a superoxide anion radical is the main free radical generated by platelets, and mitochondria are one of the superoxide anion radical sources in platelets.

To evaluate the oxidative stress under clinical conditions, a procedure is developed for the chemiluminescence determination of the total concentration of lipid hydroperoxides based on their oxidation in the presence of microperoxidase and chemiluminescence activator isoluminol in a borate buffer solution (pH 10.0). The limit of detection for linoleic acid hydroperoxide is 16 nM. The procedure is used to determine lipid hydroperoxides in follicular fluid lipoproteins and in plasma of patients undergoing extracorporeal fertilization.

The radical-producing activity of human platelets was studied using the method of activated chemiluminescence. Lucigenin, a selective probe for superoxide anion, enhanced the chemiluminescence of isolated platelets. The addition of NADH and NADPH as substrates of the oxidative systems significantly amplified the production of superoxide. The NADH- and NADPH-stimulated chemiluminescence was not affected by diphenyliodonium, an inhibitor of NADPH-oxidase, but it was lowered by 2,4-dinitrophenol. Thus, superoxide anion radical is a key free radical generated by the platelets, and one of the sources of superoxide anion radical is the mitochondria of platelets.

To determine lipid hydroperoxides, an analytical procedure was proposed based on enhanced chemiluminescence. The analytical system consisted of a lipid, Fe(II), and coumarin C-525, an enhancer of chemiluminescence. Lipid hydroperoxides were determined with spiked solutions using tert-butyl hydroperoxide as an internal standard. The analytical procedure provided a detection limit as low as 164 nM. Verification was performed by iodometric titration. The assay was used to determine total lipid hydroperoxides in food.

We proposed a procedure for the IR spectrometric determination of lipid hydroperoxides in biological systems. The main bands in the IR absorption spectra of linoleic acid and its hydroperoxide were identified, and analytical bands suitable for the determination of both compounds in their mixtures were selected. It was demonstrated that tert-butyl hydroperoxide can be used as an external standard for determining fatty acid hydroperoxides. Using the external standard method (calibration curve) for tert-butyl hydroperoxides, we calculated the concentration of linoleic acid hydroperoxide in its mixture with linoleic acid; it agreed with the specified values. Using the developed procedure, we estimated the concentration of hydroperoxide groups in natural cardiolipin. The results were compared to those obtained by an independent method (activated chemiluminescence).

Mitochondrial dysfunctions are an underlying cause of many human diseases including degenerative diseases. One of the consequences of mitochondrial dysfunctions is apoptosis of functionally active cells. During the initial stage of apoptosis, increased production of superoxide anion-radical (SAR) is observed. A promising method of SAR detection in cells and tissues is chemiluminescence (CL), primarily, in the presence of lucigenin, a SAR specific amplifier of CL. In this study a means of improving CL was proposed, and its effectiveness in detecting SAR level in living tissues of laboratory animals in hypoxia and parkinsonism models was evaluated. Aerobic (O-2 - 15 %, CO2 - 5 %, N-2 - 80 %) and anaerobic (CO2 - 5 %, N-2 95 %) gas mixtures proposed for samples aeration, maintained a constant pH of 7.4, necessary for accurate recording of CL. Using the studied method, a statistically significant increase (1.8 and 2.0 times) in SAR production level in rat heart tissue was detected with hypoxia duration of 150 to 240 minutes. In the parkinsonian model SAR production in mouse brain tissue samples of striatum and substantia nigra was 1.7 and 1.3 times higher after administration of the final dose of proneurotoxin, as compared to the control group.