Decrease In Chemiluminescence Research Articles

Fucoxanthin, A Carotenoid Derived from Phaeodactylum tricornutum Exerts Antiproliferative and Antioxidant Activities In Vitro.

Microalgae contain a multitude of nutrients and can be grown sustainably. Fucoxanthin, a carotenoid from Phaeodactylum tricornutum, could have beneficial health effects. Therefore, we investigated the anti-inflammatory, antioxidative and antiproliferative effects of fucoxanthin derived from this diatom in vitro. The effects of purified fucoxanthin on metabolic activity were assessed in blood mononuclear cells and different cell lines. In cell lines, caspase 3/7 activity was also analyzed. Nitrogen monoxide release and mRNA-expression of proinflammatory cytokines were measured. For antioxidant assays, cell free assays were conducted. Additionally, the antioxidant effect in neutrophils was quantified and glutathione was determined in HeLa cells. The results show that neither did fucoxanthin have anti-inflammatory properties nor did it exert cytotoxic effects on mononuclear cells. However, the metabolic activity of cell lines was decreased up to 58% and fucoxanthin increased the caspase 3/7 activity up to 4.6-fold. Additionally, dose-dependent antioxidant effects were detected, resulting in a 63% decrease in chemiluminescence in blood neutrophils and a 3.3-fold increase in the ratio of reduced to oxidized glutathione. Our studies show that fucoxanthin possesses antiproliferative and antioxidant activities in vitro. Hence, this carotenoid or the whole microalgae P. tricornutum could be considered as a food or nutraceutical in human nutrition, showcasing beneficial health effects.

Gold Nanoplate-Enhanced Chemiluminescence and Macromolecular Shielding for Rapid Microbial Diagnostics.

With the global rise of antimicrobial resistance, rapid screening and identification of low concentrations of microorganisms in less than 1 h becomes an urgent technological need for evidence-based antibiotic therapy. Although many commercially available techniques are labeled for rapid microbial detection, they often require 24-48 h of cell enrichment to reach detectable levels. Here, it is shown that the widely used reducing agent tris(2-carboxyethyl)phosphine (TCEP) can also act as a powerful oxidant on gold nanoplates and subsequently lead to a strong catalysis of luminol chemiluminescence. The catalytic reaction results in up to 100-fold signal enhancement and unprecedented stable luminescence for up to 10 min. However, when TCEP is exposed to microorganisms, it is oxidized by the microbial surface proteins and loses its catalytic properties, leading to a decrease in chemiluminescence. The competitive interaction of TCEP with Au nanoplates and microorganisms is used to introduce a homogenous rapid detection method that allows microbial screening in less than 10 min with a limit of detection down to 100 cfu mL-1 . Furthermore, the concept of microbial macromolecular shielding using antibody-conjugated polymers is introduced. The combination of TCEP redox activity and macromolecular shielding enables specific microbial identification within 1 h, without preconcentration, cell enrichment, or heavy equipment other than a hand-held luminometer. The technique is demonstrated by specific detection of methicillin-resistant Staphylococcus aureus in environmental and urine samples containing a mixture of microorganisms.

Free Radical Oxidation in Rat Myocardium after Maximum Permissible Hepatic Resection.

Free radical oxidation in rat myocardial homogenate was studied by chemiluminescent assay during the early terms after maximum permissible liver resection. During this period, activation of free radical oxidation was biphasic. The critical terms characterized by dramatic intensification of free radical oxidation in the myocardium are the first hour and the first day after surgery. The period from 3 to 12 h after surgery, in which the indices of chemiluminescence decrease, can be tentatively termed as the period of "putative wellbeing". Normalization of the free radical oxidation processes in the myocardium occurred by day 7 after surgery.

Determination of polydatin by gold nanoparticle-enhanced chemiluminescence of silver nitrate and luminol

ABSTRACTA novel flow injection method for the determination of polydatin is reported based on the inhibition of silver nitrate, luminol, and gold nanoparticles chemiluminescence. Under the optimum condition, the decrease in chemiluminescence was proportional to the concentration of polydatin from 1.0 × 10−8 to 1.0 × 10−5 mol/L. The detection limit was 2.1 × 10−9 mo1/L and the relative standard deviation was 2.1% for the determination of 1.0 × 10−6 mol/L polydatin. This method was successfully employed for the determination of polydatin in Polygonum cuspidatum roots and human urine.

Studies on the antioxidant activity of some thiazolidinedione, imidazolidinedione and rhodanine derivatives having a flavone core.

A series of flavonyl-2,4-thiazolidinedione, imidazolidinedione and rhodanine derivatives were tested for their antioxidant activity as scavengers of oxygen free radicals. Free radical scavenging activities, including superoxide anion radical O2•, hydroxyl radical (HO(•)) and 2,2'-diphenyl-1-picrylhydrazyl free radical have been evaluated using chemiluminescence, electron paramagnetic resonance and spin trapping with 5,5-dimethyl-1-pyrroline-1-oxide as a spin trap. Potassium superoxide in dimethylsulfoxide and 18-crown-6 ether were used for the production of O2•. Hydroxyl radical was generated using the Fenton reaction. Ten of the eleven examined compounds exhibited decrease in chemiluminescence, but there were large differences in the decrease, ranging from 16% to 89%; also, two of these compounds increased light emission by about 200%. On the contrary, all compounds tested exhibited 30-68% scavenging HO(•) and 25-96% scavenging the DPPH(•) radical respectively. Possible mechanisms are proposed to explain the results.

Interleukin-1&bgr; Increases Release of Endothelin-1 and Tumor Necrosis Factor as Well as Reactive Oxygen Species by Peripheral Leukocytes During Experimental Subarachnoid Hemorrhage

In the subarachnoid hemorrhage (SAH) blood mixes with cerebrospinal fluid, what starts immunoinflammatory processes - increased synthesis of proinflammatory cytokines, and formation of reactive oxygen species (ROS), resulting in pre-activation of different populations of peripheral leukocytes. Migration of leukocytes to the brain parenchyma through broken blood brain barrier may produce extra brain tissue injury besides of that resulting from SAH. We examined in adult rats the effect of interleukin-1β (IL-1β) neutralization on secretion of cytokines as well as production of ROS in the course of SAH. SAH was produced by injection of 150 μL of autologous arterial blood into cisterna magna. In 50% of animals, IL-1beta activity was inhibited by intracerebroventricular administration of anti-rat IL-1β antibodies. Ninety minutes or 24 hrs following surgery, blood samples were drawn from the extraorbital plexus and centrifuged to obtain two leukocyte subpopulations - polymorphonuclear (PMN) and mononuclear (MN). The chemiluminescence, a hallmark of ROS synthesis, was measured in PMNs. In supernatants from MNs cultures, concentrations endothelin-1 (ET-1), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were assessed. SAH caused the increase ofn PMNs chemiluminescence as well as the increase of production of ET-1 and TNF-α by MNs but had no influence on IL-6 concentration. Neutralization of IL-1β resulted in significant decrease of chemiluminescence as well as concentration of both ET-1 and TNF-α, while IL-6 concentration was increased. These revealed an important role of IL-1β in the activation of peripheral leukocytes in the course of subarachnoid hemorrhage.

Characterization of chemiluminescence from singlet oxygen under laminar flow conditions in a micro-channel and its quenching with beverages

Singlet oxygen was generated by reaction of sodium hypochlorite and hydrogen peroxide in a micro-channel. The two reagent solutions were delivered into the micro-channel by a syringe pump, providing a laminar flow liquid–liquid interface. The chemiluminescence from the singlet oxygen was emitted in the collapse of the interface due to molecular diffusion under laminar flow conditions. The chemiluminescence intensity was observed continuously and stably for each combination of reagents fed into the micro-channel; while, in the normal batch-type reactor the chemiluminescence peaks from singlet oxygen were observed within ca. 5 s. The features of the chemiluminescence emitted under laminar flow conditions were examined by changing the concentrations of sodium hypochlorite and hydrogen peroxide; the concentrations of 2.5 mM sodium hypochlorite and 7.5 mM hydrogen peroxide provided highest chemiluminescence intensities without bubble formation. Also, the effects of beverages, such as green tea, coffee, white wine, red wine, and sake (rice wine), on the chemiluminescence intensity as well as the concentrations of sodium hypochlorite and hydrogen peroxide were examined. The chemiluminescence intensities observed with addition of the beverages to the reagents decreased in the following orders; green tea > coffee > red wine > rice wine > white wine (being added to sodium hypochlorite); coffee > white wine > green tea > red wine > rice wine (being added to hydrogen peroxide). It was found that coffee decreased the chemiluminescence intensity ( ca. 33% chemiluminescence decrease) without altering the concentrations of sodium hypochlorite or hydrogen peroxide. The cause of the decrease in chemiluminescence with coffee is discussed.

Pulmonary surfactant protein A inhibits the lipid peroxidation stimulated by linoleic acid hydroperoxide of rat lung mitochondria and microsomes

Reactive oxygen species play an important role in several acute lung injuries. The lung tissue contains polyunsaturated fatty acids (PUFAs) that are substrates of lipid peroxidation that may lead to loss of the functional integrity of the cell membranes. In this study, we compare the in vitro protective effect of pulmonary surfactant protein A (SP-A), purified from porcine surfactant, against ascorbate–Fe 2+ lipid peroxidation stimulated by linoleic acid hydroperoxide (LHP) of the mitochondria and microsomes isolated from rat lung; deprived organelles of ascorbate and LHP were utilized as control. The process was measured simultaneously by chemiluminescence as well as by PUFA degradation of the total lipids isolated from these organelles. The addition of LHP to rat lung mitochondria or microsomes produces a marked increase in light emission; the highest value of activation was produced in microsomes (total chemiluminescence: 20.015 ± 1.735 × 10 5 cpm). The inhibition of lipid peroxidation (decrease of chemiluminescence) was observed with the addition of increasing amounts (2.5 to 5.0 μg) of SP-A in rat lung mitochondria and 2.5 to 7.5 μg of SP-A in rat lung microsomes. The inhibitory effect reaches the highest values in the mitochondria, thus, 5.0 μg of SP-A produces a 100% inhibition in this membranes whereas 7.5 μg of SP-A produces a 51.25 ± 3.48% inhibition in microsomes. The major difference in the fatty acid composition of total lipids isolated from native and peroxidized membranes was found in the arachidonic acid content; this decreased from 9.68 ± 1.60% in the native group to 5.72 ± 1.64% in peroxidized mitochondria and from 7.39 ± 1.14% to 3.21 ± 0.77% in microsomes. These changes were less pronounced in SP-A treated membranes; as an example, in the presence of 5.0 μg of SP-A, we observed a total protection of 20:4 n-6 (9.41 ± 3.29%) in mitochondria, whereas 7.5 μg of SP-A produced a 65% protection in microsomes (5.95 ± 0.73%). Under these experimental conditions, SP-A produces a smaller inhibitory effect in microsomes than in mitochondria. Additional studies of lipid peroxidation of rat lung mitochondria or microsomes using equal amounts of albumin and even higher compared to SPA were carried out. Our results indicate that under our experimental conditions, BSA was unable to inhibit lipid peroxidation stimulated by linoleic acid hydroperoxide of rat lung mitochondria or microsomes, thus indicating that this effect is specific to SP-A.

Peroxidation stimulated by lipid hydroperoxides on bovine retinal pigment epithelium mitochondria: Effect of cellular retinol-binding protein

This study analyzes the effect of cellular retinol-binding protein (CRBP), partially purified from retinal pigment epithelium (RPE) cytosol, on the non-enzymatic lipid peroxidation induced by fatty acid hydroperoxides of mitochondrial membranes isolated from bovine RPE. The effect of different amounts (50, 75 and 100 nmol) of linoleic acid hydroperoxide (LHP), arachidonic acid hydroperoxide (AHP) and docosahexaenoic acid hydroperoxide (DHP) on the lipid peroxidation of RPE mitochondria was studied; RPE mitochondria deprived of exogenously added hydroperoxide was utilized as control. The process was measured simultaneously by determining chemiluminescence as well as polyunsaturated fatty acid (PUFA) degradation of total lipids isolated from RPE mitochondria. The addition of hydroperoxides to RPE mitochondria produces a marked increase in light emission that was hydroperoxide concentration dependent. The highest value of activation was produced by LHP. The major difference in the fatty acid composition of total lipids isolated from native and peroxidized RPE mitochondria incubated with and without hydroperoxides was found in the docosahexaenoic acid content, this decreased 40.90±3.01% in the peroxidized group compared to native RPE mitochondria. The decrease was significantly high: 86.32±2.57% when the lipid peroxidation was stimulated by 100 nmol of LHP. Inhibition of lipid peroxidation (decrease of chemiluminescence) was observed with the addition of increasing amounts (100–600 μg) of CRBP to RPE mitochondria. The inhibitory effect reaches the highest values in the presence of LHP.

On-line screening method for antioxidants by liquid chromatography with chemiluminescence detection

A novel screening method for individual antioxidants in complex matrices was developed. The determination of antioxidants is based on the decrease of chemiluminescence (CL) intensity derived from luminol and superoxide anion radical (O −⋅ 2) which is generated from the enzyme reaction of xanthine oxidase with hypoxanthine. The constant CL intensity, that is recorded as background (baseline) is required for an accurate and precise detection before injection of sample solutions containing antioxidants. Each of the antioxidant separated by the liquid chromatography (LC) column was observed as a negative peak corresponding to its antioxidative potential. Some authentic antioxidants, i.e. ascorbic acid, isoascorbic acid, glutathione, (+)-catechin, (−)-epicatechin, and (−)-epigallocatechin gallate, seemed to possess scavenging activity for O −⋅ 2. However, the potential was different for each antioxidant and relatively stronger activity was found in the flavonoids. The detection limits (signal-to-noise ratio of two) of (+)-catechin and (−)-epicatechin with on-line LC-CL were 4.4 and 4.3 pmol, respectively. The proposed method was applied to the detection of antioxidants in extracts of green tea leaves ( Thea sinensis L.). Judging from the observation of negative peaks, (−)-epicatechin was the main component of antioxidants among the various intrinsic substances in green tea extracts. Detection of (−)-epicatechin in the extracts diluted 2000 times was possible, and the sensitivity was higher than that of UV detection at 280 nm. The structure of (−)-epicatechin was also identified with LC-electron spray ionization/mass spectrometry.

Effect of the platelet-activating factor antagonist RP 59227 (Tulopafant) on myocardial ischemia/reperfusion injury and neutrophil function

The effect of the platelet activating factor antagonist RP 59227 (Tulopafant) on myocardial infarct size was compared to that of a vehicle-treated control group in barbital-anesthetized dogs subjected to 90 min of left circumflex coronary artery occlusion and 5 h of reperfusion. The myocardial region at risk and infarct size were determined by the triphenyltetrazolium histochemical technique and regional myocardial blood flow by radioactive microspheres. Myeloperoxidase (MPO) activity was used as an index of neutrophil infiltration into the ischemic-reperfused area. Vehicle (n = 11) or RP 59227 (n = 12, 2.5 mg/kg i.v.) were administered 15 min prior to occlusion. Hemodynamics and regional myocardial blood flow in the ischemic-reperfused areas did not differ between the two groups throughout the experiment. In contrast, the number of dogs which developed ventricular fibrillation during occlusion and reperfusion was significantly less in RP 59227-treated dogs (8 of 11 in the control group vs. 3 of 12 in the RP 59227-treated group, p < 0.05). Myocardial infarct size expressed as a percent of the area at risk (control, 39.0 +/- 5.0; RP 59227, 24.8 +/- 3.4%) or as a percent of the left ventricle (control, 15.3 +/- 1.9; RP 59227, 9.0 +/- 1.3%) was significantly smaller in the RP 59227-treated group. Infarct size was inversely related to the collateral blood flow in the inner two thirds of the left ventricular wall of the infarct area, and this relationship was shifted downward in the RP 59227-treated group (p < 0.05). MPO activity in the border zone immediately adjacent to infarcted tissue was reduced in the RP 59227-treated dogs (control, 7.4 +/- 0.5 U/g; RP 59227, 4.1 +/- 0.4 U/g). In additional in vitro studies, the addition of PAF was found to elicit a concentration-dependent potentiation in chemiluminescence produced by purified canine neutrophils, a measure of oxygen-derived free radicals, which was stimulated with a low concentration of opsonized zymosan. Preincubation of neutrophils with RP 59227 resulted in a concentration-dependent decrease in chemiluminescence produced by PAF primed cells. Taken together, these data demonstrate that RP 59227 effectively reduces myocardial infarct size and reduces the incidence of ischemia and reperfusion-induced arrhythmias in barbital-anesthetized dogs, and support the concept that PAF plays an important role in the pathogenesis of acute myocardial infarction.

Lipoperoxidation of rod outer segments of bovine retina is inhibited by soluble binding proteins for fatty acids.

In the present study it was investigated if soluble-binding proteins for fatty acids (FABPs) present in neural retina show protection from in vitro lipoperoxidation of rod outer segment membranes (ROS). After incubation of ROS in an ascorbate-Fe++ system, at 37 degrees C during 90-120 min, the total cpm originated from light emission (chemiluminescence) was found to be lower in those membranes incubated in the presence of soluble binding proteins for fatty acids. The fatty acid composition of rod outer segment membranes was substantially modified when subjected to non-enzymatic lipoperoxidation with a considerable decrease of docosahexaenoic acid (22:6 n-3) and arachidonic acid (20:4 n-6). As a result of this, the unsaturation index, a parameter based on the maximal rate of oxidation of specific fatty acids was higher in the native and control membranes when compared with peroxidized ones. A similar decrease of chemiluminescence was observed with the addition of increasing concentrations of native or delipidated FABP retinal containing fractions to rod outer segment membranes. These results indicate that soluble proteins with fatty acid binding properties may act as antioxidant protecting rod outer segment membranes from deleterious effect.

Correlation between arachidonic acid oxygenation and luminol-induced chemiluminescence in neutrophils: Inhibition by diethyldithiocarbamate

Neutrophils from allergic subjects were hypersensitive to stimulation by low calcium ionophore concentration (0.15 μM), resulting in an increased formation of leukotriene B 4 (LTB 4), 5S-hydroxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid (5-HETE), and other arachidonic acid metabolites through the 5-lipoxygenase pathway. In parallel, luminol-dependent chemiluminescence was also higher in neutrophils from allergic patients at the basal state and after stimulation by calcium ionophore, revealing an enhancement of radical oxygen species and peroxide production. The activity of glutathione peroxidase, the main enzyme responsible for hydroperoxide reduction, was lowered in these cells. Diethyl-dithiocarbamate (DTC) induced a concentration-dependent decrease in chemiluminescence and arachidonic acid metabolism after neutrophil stimulation. These data show that the elevation of arachidonic acid metabolism in neutrophils from allergic patients is strongly correlated with oxidative status. This elevation may be the consequence of an increased cellular hydroperoxide known to activate 5-lipoxygenase (5-LOX) activity and/or an increased arachidonic acid availability, due either to phospholipase A 2 (PLA 2) activation or inhibition of arachidonate reesterification into phospholipids. Lowering this oxidative status was associated with a concomitant decrease of this metabolism. Our results suggest that the effect of DTC may be the consequence of an inhibition of peroxyl radical and cellular lipid hydroperoxide production. Thus, DTC may modulate arachidonic acid metabolism in neutrophils by modulating the cellular hydroperoxide level.

Effects of a novel perfluorocarbon emulsion on neutrophil chemiluminescence in human whole blood in vitro.

The effects have been studied of a novel perfluorochemical (PFC) emulsion (18.5% perfluorodecalin, 1.5% perfluorodimorpholine propane, 2.5% lecithin) on phorbol 12-myristate 13-acetate (PMA; 100 micrograms ml-1)-induced neutrophil chemiluminescence in citrated human whole blood in vitro. A transient, dose-dependent, decrease in chemiluminescence, to a maximum of 54% after 12 min (P < 0.05), occurred when blood was pre-incubated with 10-40 microliters of the PFC emulsion, compared to saline controls. The mean (+/- s.e.m., n = 6) chemiluminescence of neutrophils incubated with 30 microliters emulsion at 12 min following PMA stimulation (9.5 +/- 1.3 mV) was significantly lower (P < 0.05) than control (24.2 +/- 2.2 mV). Incubation of blood with lecithin up to 16 mg ml-1 and Pluronic F-68 or Pluronic PE 6800 up to 65 mg ml-1 did not affect chemiluminescence.

Differential effects of cisplatin on the production of NADH-dependent superoxide and the activity of antioxidant enzymes in rat renal cortical slices in vitro.

Cisplatin-induced cytotoxicity has been investigated with rat renal cortical slices in vitro. Incubation of renal slices with cisplatin caused an unexpected decrease in NADH-dependent. lucigenin-enhanced chemiluminescence in the homogenate of the slices in a time- and concentration-dependent fashion. Cisplatin caused a concentration-related (0.2 1 mM) decrease in the formation of NADH-dependent superoxide anion. Cisplatin (2 mM) significantly suppressed the chemiluminescence to 70% of control as early as 15 min, and to 15% after 90 min. of incubation. A decrease was also observed 90 min. after incubation of slices with 0.25 mM cisplatin. In addition, the activities of superoxide dismutase (SOD) and catalase in the slices were significantly increased after 60 min. of exposure to cisplatin (2 mM) while decreases in the activities of glutathione (GSH) peroxidase and GSSG reductase became significant at 90 and 120 min. of incubation respectively. SOD and catalase activities were increased by 1.6 and 1.5 fold respectively after 90 min. of incubation and the activities of GSH peroxidase and GSSG reductase were decreased to 82% and 72% of control, respectively at 120 min. Both dithiothreitol (2 mM), a sulphydryl agent and diphenylphenylenediamine (5 microM), an antioxidant, protected against cisplatin-induced leakage of lactate dehydrogenase, lipid peroxidation and decreases of GSH peroxidase and GSSG reductase but had no effect on the decrease of chemiluminescence caused by cisplatin. The results suggest that neither an increase in the production of NADH-dependent superoxide anion nor a decrease in activity of several antioxidant enzymes were directly responsible for cisplatin-induced lipid peroxidation.

Effects of Clindamycin and Cefuroxime on Leukocyte Membrane Receptors and Function

Normal human granulocytes and lymphocytes were preincubated in 0.5, 5, or 50 mg/l of clindamycin, and 5, 50, or 500 mg/l of cefuroxime. Incubation with clindamycin caused an increase in the proportion of granulocytes bearing receptors for the Fc portion of IgG (Fc gamma-R) and C3b (C3b-R). Random migration in capillary tubes was significantly decreased, but phagocytosis as measured by chemiluminescence was only slightly decreased. The proportion of lymphocytes bearing Fc gamma-R was decreased, while there was no effect on lymphocyte C3b-R percentage, nor on the proportion of granulocytes or lymphocytes bearing sheep erythrocyte (E) receptors. Preincubation of granulocytes in cefuroxime was not associated with changes in the proportion of receptor-bearing cells, except for a slight increase in Fc gamma-R-bearing lymphocytes at the lowest concentration tested. Tube migration was not affected but chemiluminescence was significantly decreased. Preincubation with clindamycin, although increasing the proportion of cells bearing phagocytosis-associated receptors, is thus not associated with an increased phagocytic ability, while cefuroxime incubation caused a decrease in chemiluminescence despite normal levels of receptor-positive cells.

Modulation of oxygen-free radicals from human leukocytes during halothane- and enflurane- induced general anesthesia.

Oxidative metabolism correlates with the release of microbiocidal oxygen-free radicals, measured as luminol-dependent chemiluminescence. The effect of general anesthesia on the oxidative metabolism of human leukocytes was investigated. Sixteen patients undergoing a halothane-induced general anesthesia and 14 patients receiving an enflurane-induced general anesthesia participated in the study. Halothane-induced anesthesia was accompanied both by a suppression of basic chemiluminescence and by a decrease in chemiluminescence during the phagocytosis of zymosan A. This was monitored 15 min, 30 min and 60 min after starting general anesthesia and compared to the level of chemiluminescence before starting general anesthesia. Ninety minutes after finishing general anesthesia, a significant recovery of chemiluminescence was seen to exceed the level before general anesthesia. Comparable findings were observed with enflurane-induced general anesthesia, suggesting a decreased release of oxygen-free radicals during general anesthesia, and afterwards an increase exceeding the initial level.

Effects of dietary fish oil supplementation on polymorphonuclear leukocyte inflammatory potential.

Polymorphonuclear leukocytes (PMNLs) are an important contributor to inflammation and are thus a part of the pathophysiology of many human diseases. We assessed the effect of fish oil on PMNL inflammatory potential by measuring chemiluminescence and superoxide production before and after six weeks of daily cod liver oil ingestion by healthy volunteers. Phagocytosing PMNLs demonstrated a 27% decrease in chemiluminescence (P less than 0.05) and a 64% decrease in superoxide production (P less than 0.01), following the cod liver oil supplementation. Analysis of PMNL and platelet fatty acids revealed the appearance of eicosapentaenoic acid and a significant decrease in arachidonic acid in both types of cells.

Polymorphonuclear leukocyte dysfunction associated with feline leukaemia virus infection.

The chemiluminescent characteristics of enriched (greater than 95%) peripheral blood polymorphonuclear leukocyte populations (PMN) from normal and feline leukaemia virus (FeLV)-infected cats were investigated. FeLV-infected cats demonstrated a significantly lower (P less than 0.001) PMN chemiluminescent response when compared to the response of normal age-matched controls. Normal PMN treated with FeLV-infected cat serum exhibited a depressed response in comparison to control cells. A titration of serum from infected cats supplemented with normal serum revealed a titratable suppression of chemiluminescence with increasing concentration of serum from the infected cats. However, PMN from FeLV-infected cats treated with normal serum displayed a slight increase in chemiluminescence over the same cells in autologous serum. The addition of inactivated FeLV to normal PMN caused a titratable decrease in chemiluminescence.

Action of laser radiation on peroxide chemiluminescence of wound exudate

To assess the efficacy of laser therapy in the management of unresponding wounds and ulcers the method based on the estimation of chemiluminescence of tissue fluid in the presence of H2O2 was developed. It is suggested that laser radiation-induced decrease in chemiluminescence can be attributed to the activation of catalase in tissue fluid, which has an obvious positive therapeutic effect on reparative regeneration of wounds and ulcers.