Kinetics Of Chemiluminescence Research Articles

Генерация активных форм кислорода при экспериментальном стрессе у мышей и ее коррекция

The aim of the work was to study the generation of reactive oxygen species under experimental stress in mice and their correction. The object of research were mice (n=57). In the experience of «Despair», we studied the effect of the antioxidant Mexidol-Vet® on locomotor activity, on the duodenal mucosa of mice, and the generation of reactive oxygen species by leukocytes in the blood. It was found that intramuscular administration of a 5 % solution of Mexidol-Vet® to mice at a dose of 40 mg/kg/day for 3 days before forced swimming contributes to a significant increase in the duration of horizontal swimming and a decrease in vertical locomotor activity by 3.26 times, compared with individuals receiving placebo. In the stress model, the stress-protective effect of the drug Mexidol-Vet was established in relation to the adrenal glands, duodenal mucosa (Pauls index was 0.66), «respiratory burst» and generation of reactive oxygen species by blood leukocytes (the maximum intensity and light sum of chemiluminescence were significantly higher than the value mice with placebo by 233.25 % and 231.28 %, respectively. The linear dependence of the variation in the kinetics of blood chemiluminescence is reflected in the formula: y= -3020.7x + 10793. The significance value of the approximation of the trend line was 0.991.

The Dynamics of the Formation of Cytochrome c Complexes with Anionic Lipids and the Mechanism of the Production of Lipid Radicals Catalyzed by These Complexes

In the present work, the recorded kinetics of chemiluminescence enhanced by coumarin 334 indicated that the complexes of cytochrome c (Cyt) with anionic lipids (Cyt-AL), such as cardiolipin (CL) and phosphatidic acid (PA), when added to mitochondrial and cytoplasmic membranes, are capable of catalysing reactions of lipid free radical formation. The effect of Cyt-CL complex was studied on mitochondria isolated from the liver of male Wistar rats and male outbred mice, as well as on erythrocytes isolated from the blood of male Wistar rats. It was shown that complex Cyt-PA exerts a peroxidase effect similar to the effect produced by Cyt-CL. Upon exposure to Cyt-CL, the formation of free radicals was more prominent in mitochondrial ghosts (mitochondria subjected to freeze-thawing and washed by several precipitation–resuspension cycles) than in intact mitochondria. This suggests that Cyt-CL does not pass through biological membranes: even if it penetrates into them, it probably gets stuck in the phospholipid bilayer. Thus, the previously discovered cytotoxic effect of Cyt-CL on cancer cells is most likely due to peroxidation of the cytoplasmic membrane, but not of the inner membrane of mitochondria.

Extreme Kinetics of Chemiluminescence in the Initiated Oxidation of Vegetable Lipids

During the oxidation of sunflower oil initiated by 2,2'-azo-bis-isobutyronitrile, which was used in this study as the model lipid system of plant origin, the previously unobserved form of kinetic chemiluminescence curves has been discovered. At the end of the induction period, during which chemiluminescence was suppressed by the antioxidants present in sunflower oil, instead of the expected smooth S-shaped output of the luminescence intensity at a significantly higher stationary level, a sharp surge in intensity was observed with its subsequent decrease to the stationary level. The standard kinetic scheme, which is used in most works on the effect of antioxidants on chemiluminescence in the chain free-radical oxidation of hydrocarbons, cannot explain the shape of the obtained kinetic curves. To explain the discovered phenomenon, an extended kinetic scheme, which takes into account the reactions of the initiator isobutyronitrile-peroxide radicals and their conversion to methyl-peroxide radicals, is proposed. It is shown that the observed extreme kinetics is possible only in the case of quantum yields of the chemiluminescence from the reaction of the initiator isobutyronitrile-peroxide radicals with the substrate peroxide radicals, which are 1–2 orders of magnitude higher than the quantum yields of other chemiluminescent reactions.

THE INCREASED KINETICS OF H2O2-INDUCED CHEMILUMINESCENCE IN THE PATIENTS WITH LONG-TERM CONSEQUENCES AFTER CEREBRAL CONTUSION

Purpose of the study. The aim was to study in the patients with long-term consequences after cerebral contusion the intensity of spontaneous and H2O2-induced chemiluminescence in order to evaluate the early fast-flowing reactions caused by oxidative stress and associated with the formation of primary radicals such as free radical oxidations.
 Materials and Methods. Forty-two patients with long-term consequences after cerebral contusion were investigated (39,04 ± 12,84 years mean age; mean onset years 32,56 ± 6,4) where both spontaneous and H2O2-induced chemiluminescences were measured directly by HPLC-chemiluminescence assay.
 Results. The study have showed that sera of the investigated patients with long-term consequences after cerebral contusion have the increased H2O2-induced chemiluminescence associated with the high amplitude of «fast» burst and the tendency to increase of spontaneous chemiluminescence (p = 0,039 and p = 0,58, accordingly). Thus, the patients with longterm consequences after cerebral contusion showed the abnormal high kinetics of H2O2-induced chemiluminescence (p < 0,05). The statistically significant increase serum Н2О2-induced chemiluminescence intensity detected in examined patients (3085,6 ± 114,2 vs 669,1 ± 214,83 controls) have showed the development of certain oxidative stress processes in this category of patients associated with the increasing of primary free radical reactions and their activity were getting increased with the progression of the disease duration (p < 0,05).
 Conclusions. The study provides the novel data revealing the increased kinetics of H2O2-induced chemiluminescence in the patients with long-term consequences after cerebral contusion accompanied by the tendency to increase of spontaneous chemiluminescence that may play the certain pathogenetic role.

Antioxidant activities of Geranium sanguineum L. polyphenolic extract in chemiluminescent model systems

The aim of this study is to assess the antioxidant activities of Geranium sanguineum polyphenolic extract in chemiluminescent model systems by calculating the constants of inhibition towards different reactive oxygen species (ROS). The kinetics of lucigenin-enhanced chemiluminescence was examined in three chemical systems designed for generation of ROS (OH, O2−, H2O2) and in one system with FeSO4 added as a chelator. Antioxidant enzyme activities of superoxide dismutase and glutathione reductase were also evaluated. All the calculated constants of inhibition were compared to vitamin C and vitamin E values obtained earlier. Based on the results we can make the following major conclusions:1)the polyphenol complex reacts against all studied ROS (H2O2, OH, O2−) with various efficacy. It exerts lower anti-oxidant effects when compared to standards such as vitamin C and vitamin E.2)the polyphenol complex has pronounced chelation properties against Fe2+, which is of extreme biological importance.3)The reference concentration (0.1 mg/ml) is most appropriate for therapeutic purposes.All obtained data contribute to the elucidation on the therapeutic and prophylactic reactive mechanisms of polyphenols extracted from Geranium sanguineum L.

Changes in the kinetics of plasma chemiluminescence as a measure of systemic oxidative stress in humans

Oxidative stress acts as a pathogenetic factor in many diseases; estimating its level is important for early diagnosis and therapy adjustment. The antioxidant status was evaluated for the blood plasma. A set of chemiluminescence (CL) kinetic-curve parameters (latent period τlat and analytical signal increment ΔI CL) in a 2,2’-azo-bis(2-amidinopropane)dihydrochloride–luminol system were proposed for estimating the oxidative stress level. Uric acid and albumin were identified as major components that are responsible for the changes in the plasma CL kinetic curve. UV light caused oxidative modification of serum albumin in a dose-dependent manner, thus enhancing its antioxidant properties. Changes in plasma CL kinetics were proposed as a means to measure oxidative stress in the human body.

DYNAMICS OF HEMOSTASIS AND NEUTROPHIL FUNCTIONAL ACTIVITY CHANGES IN PATIENTS WITH VARIOUS SENSITIVITY TO ACETYLSALICYLIC ACID IN ACUTE MYOCARDIAL INFARCTION

Aim. To study in dynamics the specifics of hemostasis and functioning of neutrophilic granulocytes in patients with acute myocardial infarction (MI) sensitive and resistant to acetylsalicylic acid (ASC). Material and methods. Totally, 53 patients included during first 24 hours from MI onset. Controls were 50 relatively healthy volunteers. All patients before treatment and revascularization were assessed for resistance to ASC and selected to groups as sensitive (SASC) and resistant (RASC). In complex therapy there was double antiplatelet therapy (ASC+clopidogrel). The parameters of vessel-platelet and plasma hemostasis were assessed. Via the chemiluminescent analysis we studied functional activity of neutrophils. Results. In RASC patients with MI on 1st and 10th day we found increased ADP aggregation of thrombocytes (ADP 0,1 mcM) and increase of von Willebrand factor. On 10th day in SASC patients there was decrease of ADP aggregation (ADP 5 mcM), von Willebrand factor increases. Not related to ASC sensitivity, in MI patients there is increase of SFMC, thrombin time is increased and D-dimer is low. Kinetics of chemiluminescence of neutrophils in MI patients differs from controls only by increased time of reached maximum. In ASC resistant patients on 1st day of evaluation there is decrease of neutrophil activation index, which gets to normal by 10th day of treatment. Conclusion. In RASC MI patients there is increased ADP aggregation of platelets, decrease of platelets number and increase of von Willebrand factor levels. Thrombosis risk in RASC patients on 10th day of treatment is caused by remaining disordered vessel-platelet hemostasis and increased spontaneous platelets aggregation. Plasmatic hemostasis on 1st and 10th days of MI shows activated onset of clotting with increase of clotting duration and significant decrease of D-dimer. In MI there is slowed velocity of development of “respiratory boost” in neutrophilic granulocytes that is probably related to compensatory processes in organism and double antiplatelet therapy which is antiinflammatory as well.

Reactive Oxygen Species Registration in Planarian Regeneration

<p class="1Body">Reactive oxygen species (ROS) are directly involved in cell proliferation, differentiation and apoptosis in a variety of organisms. We studied kinetics of own luminescence induced by changes of ROS in early stages of planarian regeneration. Kinetics of chemiluminescence were measured in intact planarians and the same individuals after decapitation within 15 hours. We analyzed the traumatic fluorescent signal obtained as the difference between kinetics of intact and decapitated planarians. It was found that regeneration is accompanied by changes in the content of ROS correlated with the energy-intensive process in regenerating planarians. Oxidative stress was caused by damage to cell membranes in the dissection of the planarian and it was accompanied by a drop in the intensity of luminescence with a time constant of about 3.6 hours. Phagocytosis of dying cells by neoblasts was accompanied by an increase of the luminescence intensity after 2 - 3 hours after decapitation. Neoblast mitosis was described by two maximums of luminescence over 5.1 hours and 8.3 hours after decapitation. For the first time we demonstrated the opportunity of registering the physiological state of pluripotent stem cells at the level of the organism <em>in vivo</em>.</p>

Simultaneous Evaluation of Chemiluminescence and Bioluminescence in a Phagocytic System

The spectra of luminol-dependent chemiluminescence of leukocytes, forming as a result of their oxygen-dependent bactericidal systems activation, and bacterial bioluminescence of Escherichia coli recombinant strain with cloned lux operon, used as the object of phagocytosis, are not identical. Mutual overlapping of these spectra reaches 87%, including overlapping of the photoemission maximums. However these spectra can be evaluated separately in the short-wave "arm" of the chemiluminescence spectrum (<420 nm) and the long-wave "arm" of the bioluminescence spectrum (>560). The kinetics of luminol-dependent chemiluminescence of phagocytes and of bacterial bioluminescence in their mixtures is characterized by mutually dependent phase-wise changes in the intensity of the analyzed parameters.

Comparison of isothermal and non-isothermal chemiluminescence and differential scanning calorimetry experiments with benzoyl peroxide

AbstractDifference in the kinetics of chemiluminescence (CL) and differential scanning calorimetry records for decomposition of originally solid benzoyl peroxide continuing as a melt reaction was outlined. While the main portion of heat measured by DSC is released in the spontaneous decomposition of benzoyl peroxide starting as a homolytic scission of peroxidic bonds, the CL light emission in oxygen comes presumably from the subsequent disproportionation reaction of polyphenyl peroxyl radicals and monitors the induced decomposition of peroxide. Thermogravimetry revealed that oxygen remains partially bound to the products of benzoyl peroxide decomposition.

Superoxide anion production by neutrophils is associated with prevalent clinical manifestations in systemic lupus erythematosus

To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus (SLE), the superoxide anion (O2-) production by neutrophils, mediated by FcgammaR and FcgammaR/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: (1) manifestations associated with the occurrence of cytotoxic antibodies (SLE-I group); (2) manifestations associated with circulating immune complexes (IC; SLE-II group), and (3) manifestations associated with IC and cytotoxic antibodies (SLE-III group). O2- production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with IC-IgG opsonized or not with complement. No difference in O2- production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: (1) SLE-I neutrophils showed lower O2- production mediated by the IgG receptor (FcgammaR) with the cooperation of complement receptors (FcgammaR/CR) than observed in the SLE-II, SLE-III, and healthy groups; (2) neutrophils from the SLE-II group showed a decreased [Formula: see text] production mediated by FcgammaR/CR compared to the SLE-III group, (3) SLE-III neutrophils produced more O(2)(-) than neutrophils from the SLE-II and control groups, and (4) CR showed inefficiency in mediating the O2- production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence (CL; Tmax and CLmax) disclosed differences only for the SLE-I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by FcgammaR/CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.

Kinetics of OH chemiluminescence in the presence of silicon

Ultraviolet emission from the OH(A–X) transition near 307 nm has been measured in a shock-tube for T = 1050–1400 K and P ≈ 1.2 atm. Experimental mixtures of H 2/SiH 4/O 2/Ar and kinetics calculations were used to identify the elementary reaction forming electronically excited OH (OH ∗) in a Si-containing environment and directly measure its absolute rate coefficient. The primary Si-containing reaction found to form OH ∗ is (R0) SiH + O 2 = OH ∗ + SiO with a rate expression of k 0 = 1.5 × 10 7 exp ( + 16.4 kcal/RT ) ± 2.3 × 10 10 cm 3 mol −1 s −1 This work provides insights into the mechanisms of combustion processes involving silicon.

Chemiluminescence Determination of Cyanide Ions

It was found that alkaline solutions of luminol exhibit chemiluminescence in the presence of p-nitrobenzaldehyde (p-NBA), hemin, and cyanide ions. Air oxygen dissolved in the solutions is an essential component of the process. The kinetics of luminol chemiluminescence in the presence of p-NBA, hemin, and cyanide ions indicates the catalytic nature of the process. A scheme was proposed for the series of reactions resulting in chemiluminescence and generated by superoxide radicals formed in the p-NBA-catalyzed reaction between hemin-activated air oxygen and hydrated p-NBA species. A procedure was developed with a determination limit of (1.0 ± 0.3) × 10−7 mg/mL (n = 5, P = 0.95) for cyanide ions.

Inertness of C60 fullerene toward RO2 · peroxy radicals

The reactivity of fullerene C60 toward peroxy radicals RO2· was tested by the chemiluminescence method. A comparison of the influence of C60 and known inhibitors on the kinetics of liquid-phase chemiluminescence (CL) during oxidation of a series of hydrocarbons (ethyl-benzene, cyclohexane, n-dodecane, and oleic acid) shows that the fullerene does not react with the RO2· radicals. A sharp decrease in the CL intensity observed upon C60 addition is caused by the quenching of CL emitters with fullerene but not by inhibition of hydrocarbon oxidation.

Peroxynitrite-Initiated Oxidation of Acetoacetate and 2-Methylacetoacetate Esters by Oxygen: Potential Sources of Reactive Intermediates in Keto Acidoses

Oxidative stress is believed to play a role in the pathogenesis of several diseases, including diabetes and inborn errors of metabolism. The types of oxidative damage observed in these pathologies have been attributed to the excessive production of reactive intermediates relating to the accumulation of toxic metabolites. The production of extremely oxidizing peroxynitrite can also be high in these pathologies. We study here the oxidation initiated by peroxynitrite of the ethyl esters of acetoacetate (EAA) and 2-methylacetoacetate (EMAA), metabolites that accumulate in diabetes and isoleucinemia, respectively. Oxygen consumption studies have confirmed that peroxynitrite promotes the aerobic oxidation of EAA and EMAA in phosphate buffer. These reactions were accompanied by ultraweak light emission, which probably arises from triplet carbonyl products formed by thermolysis of dioxetane intermediates. The kinetics of oxygen uptake and chemiluminescence by EAA and EMAA was strongly affected by the phosphate ion, known to catalyze carbonyl enolization and nucleophilic additions to carbonyls. The reaction pH profiles obtained by oxygen consumption and chemiluminescence measurements indicated that the peroxynitrite anion was the initiator of EAA and EMAA aerobic oxidation. EPR spin-trapping studies with the spin traps 3,5-dibromo-4-nitrosobenzenesulfonic acid and 2-methyl-2-nitrosopropane showed the intermediacy of methyl and a carbon-centered radical (*CH2COR) in the oxidation of EAA by peroxynitrite. In the case of EMAA, a tertiary carbon-centered radical (*EMAA) and an acyl radical were detected, the latter probably resulting from the cleavage of a triplet carbonyl product. Superstoichiometric formation of acetate from both substrates confirmed the occurrence of oxygen-dependent chain reactions, here proposed to be initiated by one-electron abstraction from the enolic form of the substrates. The free radicals and electronically excited species generated in the oxidation of EAA and EMAA may help shed further light on the molecular basis of these diseases.

Properties of kinetics of chemiluminescence of luminol excited by a nitrogen laser

The kinetics of chemiluminescence of luminol C8H7N3O2 excited by a pulsed nitrogen laser is studied The kinetics of chemiluminescence of free luminol molecules is compared with that of luminol molecules in the complex UO2(C8H6N3O2)2. Photochemical consequences of excitation of the UO2(C8H6N3O2)2 are considered.

Chemiluminescence from tetramethyldioxetane in poly(methyl methacrylate) and polystyrene

The kinetics of chemiluminescence accompanying the thermal decomposition of tetramethyl-1,2-dioxetane (TMD) in a polymethyl methacrylate matrix and a polystyrene matrix has been investigated at isothermal and non-isothermal conditions. Induced decomposition of TMD by excited activator—9,10-dibromoanthracene (DBA)—has been observed for a PMMA matrix and the energy transfer radius for this process has been estimated. The different values of activation parameters obtained by both methods are discussed.

Two processes responsible for chemiluminescence development in the course of iron-mediated lipid peroxidation.

The kinetics of chemiluminescence (CL) accompanying Fe(2+)-induced lipid peroxidation (LPO) in liposome suspension has been investigated. A sequence of stages was observed, namely: (1) fast CL flash (FF); (2) latent period (LP); (3) slow CL flash (SF) and (4) stationary chemiluminescence (SL). The first three stages are known to reflect the Fe(2+)-mediated LPO process. In spite of the fact that at the stage of SL Fe2+ has completely oxidized and MDA has not accumulated, CL intensity was found to increase and after 0.5-1 h reached a value that was several times higher than SF amplitude. The maximal SL level was linearly dependent on the initial Fe2+ concentration and was not dependent on liposome concentration in the suspension. The nature of the processes responsible for CL emission at the stage of SL has been investigated using free radical reaction inhibitors and measurement of CL spectra. The SL spectrum was observed in the red region (lamda > 590 nm) in contrast to the SF CL spectrum (maximum at 540nm). SL amplitude was strongly inhibited by sodium azide (40%), superoxide dismutase (SOD) (30%), desferrioxamine and EDTA (30%), whereas mannitol, ethanol, alpha-tocopherol and butylated hydroxytoluene were ineffective. The data obtained indicate that CL at the stage of SL is not directly related to LPO process, i.e. lipid free radical recombination. The mechanism of stationary CL generation is discussed.

Model components of luminol chemiluminescence generated by PMNL

The production of activated oxygen species (AOS) by neutrophils (PMNL) is thought to play a key role in the host defence against invading microorganisms. However, the oxygen metabolites are toxic not only to the invading bacteria but also to the surrounding tissue. The oxidative metabolites production can be evaluated by means of chemiluminescent methods. In this study, the possibility of a new analytical approach for quantitative assessment of chemiluminescent kinetics (AOS generation) of isolated PMNL was estimated. Based on the assumption that the kinetics of luminol-amplified chemiluminescence (LCL) of stimulated PMNL possesses a time-probabilistic nature, this kinetics was described with three components. These components, obtained from different investigated systems, were analyzed and a conclusion was made that the first and the second component represent the processes resulting in extra-and intracellular myeloperoxidase (MPO)-dependent light emission (AOS generation), respectively. The second component was found to be completely dependent on the stimulus ingestion. The third component was not completely MPO-dependent and complicated for interpretation. This component was weakly dependent on the stimulus ingestion, and presents at least some intracellular processes different from those presented by the second component. A conclusion is made that the examined approach for analysis of LCL kinetics allows an assessment of extra-and intracellularly generated quantities of AOS by stimulated PMNL. The assessment could be done for emitting systems in which no additional modificators are used.

Rate constants for the reaction of peroxyl free radical with flavonoids and related compounds as determined by the kinetic chemiluminescence method

The kinetic chemiluminescence method was applied to determine rate constants (ks) for the reaction of the peroxyl radical from diphenylmethane, ROO˙, with a number of flavonoids, catechol derivatives as well as two ‘standard’ phenolic antioxidants at 50 °C in chlorobenzene. It was found that the kinetics of the interaction of ROO˙ with the majority of flavonoids and catechols is complicated by a slow process which could be optimally simulated by a mono-molecular transformation of the respective semiquinone radicals. The rate constants for this transformation (k17), indirectly derived from the kinetics of chemiluminescence are listed in parentheses. The following rate constants k5(in dm–3 mol–1 s–1) and k16(in s–1) have been obtained: quercetin, 2.1 × 107(2.0); dihydroquercetin, 1.9 × 107(0.92); luteolin, 2.2 × 107(0.8); catechin, 6.6 × 106(7.5); fisetin, 1.2 × 107(1.1); naringenin, 3.4 × 103(0.2); kaempferol, 1.0 × 106(0.8); caffeic acid, 1.5 × 107(1.9); 3,5-di-tert-butylcatechol, 1.9 × 107(0.65); nordihydroguaiaretic acid, 1.0 × 107(∼ 0); α-tocopherol, 8.5 × 106(0); 2,6-di-tert-butyl-4-methylphenol (BHT), 3.6 × 104(0).