Use Of Chemiluminescence Research Articles

Hormones and depression in the advanced age.

In older people, depression and mental disability are more frequently present than in younger subjects. It is found that depressionis a risk factor for dementia, just as dementia is a risk factor for depression. In turn, both disturbances are known to be influenced by hormones. The present study aimed to see whether the hormonal changes in subjects over 75 years old correlate with the symptoms of depression measured using the Geriatric Depression Scale (GDS). In a group of patients aged over 75 years, concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), oestradiol, testosterone, dehydroepiandrosterone sulphate (DHEAs), and cortisol were measured in serum with the use of chemiluminescence. The symptoms of depression were estimated by GDS, and the mental functions were assessed by the Mini-Mental State Examination (MMSE). The correlations between the obtained results were estimated by Spearman's test. A significant correlation between GDS and MMSE scores was observed in the investigated patients. Some statistically significant correlations concerning cortisol and testosterone with GDS were observed in women, but not in men. On the other hand, no significant correlations between concentrations of FSH, LH, DHEAs, and oestradiol with GDS were noticed. Our data support the role of cortisol (possibly secreted during chronic stress) in the risk of depression. The gender difference in the mechanism of depression and stress in older age could be also hypothesized.

Efficacy of chemiluminescence in the diagnosis and screening of oral cancer and precancer: a systematic review and meta-analysis

IntroductionEarly detection of potentially malignant oral cavity disorders is critical for a good prognosis, and it is unclear whether the use of chemiluminescence as an adjunctive diagnostic screening method improves diagnostic accuracy. ObjectiveThis systematic review and meta-analysis was performed to assess the accuracy of chemiluminescence for diagnosis of oral cancer and precancerous lesions. MethodsSixteen prospective and retrospective studies from PubMed, Cochrane database, SCOPUS, Web of Science, Embase, and Google Scholar were reviewed. Oral mucosal disorder, as detected by chemiluminescence, was compared with oral mucosal disorder detected by toluidine blue or visual examination. True-positive, true-negative, false-positive, and false-negative rates were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies tool (ver. 2). ResultsSensitivity, specificity, negative predictive value, and diagnostic odds ratio (DOR) of the use of toluidine blue were 0.832 (95% confidence interval [CI] 0.692–0.917), 0.429 (95% CI 0.217–0.672), 0.747 (95% CI 0.607–0.849), and 4.061 (95% CI 1.528–10.796; I2=9.128%), respectively. The area under the summary receiver operating characteristic (SROC) curve was 0.743. Compared with toluidine blue, as used in 12 studies, chemiluminescence had a higher sensitivity (0.831 vs. 0.694); it had a lower specificity (0.415 vs. 0.734), negative predictive value (0.674 vs. 0.729), and DOR (3.891 vs. 7.705). Compared with clinical examination, as used in three studies, chemiluminescence had lower DOR (4.576 vs. 5.499) and area under the curve (0.818 vs. 0.91). ConclusionAlthough chemiluminescence itself has good sensitivity for diagnostic work-up of oral cancer and precancer, the diagnostic accuracy of chemiluminescence is comparable to or worse than toluidine blue and clinical examination. Diagnostic accuracy was therefore insufficient for reliable use of chemiluminescence alone.

Activity-Based Optical Sensing Enabled by Self-Immolative Scaffolds: Monitoring of Release Events by Fluorescence or Chemiluminescence Output.

Functional molecular scaffolds comprised of self-immolative adaptors are being used in widespread applications in the fields of enzyme activity analyses, signal amplification, and bioimaging. Optically detected chemical probes are very promising compounds for sensing and diagnosis, since they present several attractive features such as high specificity, low detection limits, fast response times, and technical simplicity. During the last two decades, we have developed several distinct molecular scaffolds that harness the self-immolative disassembly feature of these adaptors to amplify chromogenic output for diagnosis and drug delivery applications. In order to study the molecular behavior of the various amplification systems, an optical output, used to monitor the progress of the disassembly pattern, was required. Therefore, over the course of our research, diverse molecular scaffolds that produce an optical signal in response to a disassembly step, were evaluated. These optically active scaffolds have been incorporated into self-immolative dendrimers and self-immolative polymers to implement unique disassembly properties that result with linear and exponential signal amplification capabilities. In addition, some scaffolds, aimed for linker technology, were used in delivery systems to monitor release of drug molecules. The optical signal used to monitor the release event could be produced by analysis of reporter molecules with chromogenic or fluorogenic properties. Recently, we have also developed molecular scaffolds modified to produce a chemiluminescent signal to monitor the self-immolative disassembly step. The main advantage of these scaffolds over others is the use of chemiluminescence as an output signal. It is well-known that chemiluminescence is considered as one the most sensitive diagnostic methods due to its high signal-to-noise ratio. The unique structures of the self-immolative chemiluminescence scaffolds have been used in the design of three different distinctive concepts: self-immolative chemiluminescence polymers, auto-inductive amplification systems with chemiluminescence signal and monitoring of drug release by a chemiluminescence output. Furthermore, we reported the design and synthesis of the first theranostic prodrug for the monitoring of drug release achieved by a chemiluminescence mode of action. Quinone-methide elimination has proven to serve as a valuable functional tool for composing molecular scaffolds with self-immolative capabilities. Such scaffolds function as molecular adaptors that can almost simultaneously release a target molecule with an accompanied emission of a light signal that is used to monitor the release event. We anticipate that these self-immolative scaffolds will continue to find utility as functional linkers in various chemical and biological research areas such as drug delivery, theranostic applications, and as molecular sensors with signal amplification.

Excited OH kinetics and distribution in H2 premixed flames

With the aim of understanding the link between excited OH (OH∗) and ground species, we have investigated its distribution and kinetics in steady planar premixed H2-O2-N2 flames. We find that the OH∗ distribution mimics the two-layer chemical structure of the underlying host H2 flame, with a thin fuel consumption layer where OH∗ is out of equilibrium and a thicker downstream recombination tail where OH∗ relaxes to thermodynamic equilibrium with OH. This distribution can be characterized by only two representative concentrations: (i) the peak concentration at the fuel consumption layer, and (ii) the final downstream equilibrium concentration. A map of their ratio in an equivalence-dilution plane reveals the gradual transition between two limit-flame types: low-dilution flames emit with similar intensities from both regions, whereas highly-diluted flames emit more strongly from the fuel consumption layer. The relevance of these findings to the detection and to the rational, quantitative use of chemiluminescence is discussed.

Quantitative fuel-to-air ratio determination for elevated-pressure methane/air flames using chemiluminescence emission.

The fuel/air ratio (FAR) in a methane-air Hencken flame at pressures of 1-5 bar is measured using the chemiluminescence-based method. Emission spectra are used to investigate the effects of pressure on the OH* (308 nm), CH* (430 nm), and C2* (500 nm) emissions and the effect on equivalence ratio determination from the ratios of these emission peaks. Both OH*/CH* and C2*/CH* ratios are linear to FAR at atmospheric pressure. At elevated pressures, C2*/CH* remains roughly linear to FAR, while OH*/CH* becomes highly nonlinear. There are significant spectral contributions from continuum radiation at higher pressures, likely due to increasing soot production. Therefore, while it is a truly passive and nonintrusive diagnostic method, the use of chemiluminescence for FAR determination at high pressures could be limited. Possible improvements to the measurement setup and future studies are discussed.

Development of Highly Sensitive Analytical Methods for Biologically Relevant Materials and Their Pharmaceutical Applications

One important aspect of analytical chemistry research in the pharmaceutical sciences is the development of diagnostic and therapeutic analyses for disease, and the development of analytical methods for elucidating the causes of disease. I have been focusing on developing a highly sensitive method for measuring trace amounts of specific components in biological samples. This research can be roughly divided into three approaches: the use of immunoassays and DNA hybridization as methods utilizing specific affinities, the use of capillary electrophoresis as a highly sensitive and rapid separation method, and the use of chemiluminescence and bioluminescence reactions. The components being measured are compounds such as hormones, tumor markers, drugs, reactive oxygen species and genes in biological samples for the purpose of developing therapies for the prevention and treatment of diseases.

Copolymerization of propylene and methyl vinyl ketone with metallocene catalysts: Synthesis, properties, and thermal and photooxidation of modified polypropylene

The copolymers of propylene and methyl vinyl ketone are synthesized at 60°С by copolymerization in the propylene bulk in the presence of the polymethylaluminoxane-activated metallocene catalysts, namely, the isospecific С2-symmetric metallocene catalyst rac-Me2Si(2-Me-4-PhInd)2ZrCl2 and the syndiospecific Сs-symmetric metallocene catalyst Ph2ССpFluZrCl2, and characterized. It is shown that a noticeable insertion of methyl vinyl ketone into a polypropylene chain is possible during copolymerization initiated by the syndiospecific catalytic system, whereas in the case of the isospecific system, the insertion of methyl vinyl ketone is hindered. The thermal oxidation of the resulting polymers is studied. With the use of chemiluminescence, the accumulation of peroxy macroradicals under the action of daylight in samples based on isotactic and syndiotactic polypropylene is detected. It is found that even a low (0.2 mol %) content of methyl vinyl ketone endows polypropylene with the capability to undergo rapid and controlled degradation under natural conditions.

Ultrasensitive quantitation of MicroRNAs via magnetic beads-based chemiluminesent assay

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level, and their aberrant expression occurs during the development of malignant diseases. Recently, miRNAs have been proposed as potential prognostic and predictive biomarkers for early diagnosis. However, a major obstacle in rapid miRNA analysis from real samples is the lack of ultrasensitive and quantitative techniques. In this regard, the use of chemiluminescence (CL) system offers a highly sensitive strategy for detecting miRNAs. In this article, an ultrasensitive approach has been established for the quantification of miRNAs, using magnetic beads (MBs) and alkaline phosphatase (AP)-based CL system. This technique depends on sandwich hybridization among MBs-labeled capture probes, target miRNAs and biotin-labeled reporter probes, conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotin-labeled reporter probes, and CL detection of AP-linked targets. Detection of miR-21 with this technique demonstrated a high selectivity and an ultralow limit of detection (LOD) of 60 fM with an extraordinarily wide range of six orders of magnitudes. The quantitation could be achieved by direct detecting target miRNA in serum samples within a total time of 1.5 h and did not require reverse transcription and polymerase chain reaction (PCR) amplification. Therefore, this developed method shows great potential for early cancer diagnosis based on miRNAs as biomarkers.

Little evidence for the effectiveness of chemiluminescence and autofluorescent imaging devices as oral cancer screening adjuncts.

Medline/PubMed. Primary studies where an optical device was used for investigation, screening or as a diagnostic tool for OSCC or OPMD were considered. Data were abstracted by two reviewers independently and the biological plausibility, technical feasibility and diagnostic performance assessed. Twenty-five studies were included, 13 involving the use of chemiluminescence and 12 using autofluorescence with some using both. Chemiluminescence showed sensitivity at detecting any OPMDs and oral cancer, but preferentially detects leukoplakia and may fail to spot red patches. The additive use of toluidine blue may improve specificity. Tissue autofluorescence is sensitive at detecting white, red and white and red patches, and the area of fluorescence visualisation loss often extends beyond the clinically visible lesion. However, in addition to OPMDs, it may detect erythematous lesions of benign inflammation resulting in false-positive test results. In agreement with previous reviews, there is inadequate evidence to draw valid conclusions on the effectiveness of chemiluminescence and autofluorescent imaging devices as screening adjuncts. There is limited evidence for their use in primary care, and these tools are better suited to specialist clinics in which there is a higher prevalence of disease and where experienced clinicians may better discriminate between benign and malignant lesions.

Immunoblotting of Antigens: Whole, Strip, and New-Line Nitrocellulose Membrane Immunoblotting Using the Chemiluminescence Technique.

Antigen detection is a well-known tool in the scientific world that is used by clinicians and researchers to detect specific antigens in diagnosing diseases or for other medical/environmental discoveries. Antigen detection is introduced in various forms over the past decades. These techniques are often evaluated by their sensitivity, accuracy, and ease of use. One technique that has provided many advantages over typical immunochemical staining is the use of chemiluminescence. This technique has been used in various scientific fields, anywhere from clinical diagnosis to environmental research. The emission of visible radiation by compounds once exposed to sunlight has been known for centuries and currently is the main principle for chemiluminescence. Here, we introduce three different chemiluminescence techniques that are widely used in immunodetection of antigens: (a) whole membrane chemiluminescence detection, (b) strip membrane chemiluminescence detection, and

Red-shifted emission from 1,2-dioxetane-based chemiluminescent reactions.

Commercial chemiluminescent reagents emit across a broad portion of the electromagnetic spectrum (400-500 nm). A challenge to the use of chemiluminescence to monitor biological processes is the presence of interfering substances in the biological optical window. In the present study, longer wavelength emitting fluorophores (the organic dyes Alexa 568 and Alexa 647), and a semiconductor nanoparticle (QDOT800) were used to red-shift the emission from commercially available 1,2-dioxetane-based chemiluminescent substrate reactions. By adding non-conjugated fluorescent emitters into chemiluminescent reaction mixtures, an emission peak occurred at the predicted wavelength of the fluorescent emitter. The excitation and emission from QDOT800 was preserved in the presence of a 100 µm-thick glass barrier separating it from the chemiluminescent reaction components. The maximum tissue phantom penetration by QDOT800 emission was 8.5 mm; in comparison, the native chemiluminescent emission at 500 nm was unable to penetrate the thinnest tissue phantom of 2.5 mm. The described method for red-shifted emissions from chemiluminescent reactions does not require direct interaction between the chemiluminescent reaction and the fluorescent emitters. This suggests that the mechanism of chemiluminescent excitation of fluorophores and QDOT800 is not exclusive to chemiluminescence resonance energy transfer or sensitized chemiluminescence, but rather by broad energization from the native chemiluminescent emission.

Sensitive luminescence techniques to study the early stages of polymer oxidation

This paper describes recent developments in the use of chemiluminescence (CL) and profluorescent nitroxides (PFNs) in probing the “induction period” of polymer oxidation. CL measures the instantaneous rate of reaction of hydroperoxides responsible for initiating degradation and the spreading of oxidation, while PFNs can be used to measure the concentration of alkyl radicals produced in oxidation events and thus provide an integrating sensor for the extent of cumulative damage. The PFN additive acts as an oxidation retarder by competing with oxygen to scavenge the alkyl radicals that generate chain carrying peroxy radicals and so mirrors the performance of hindered amine stabilisers (HAS) in one part of their stabilisation cycle. Using the example of polypropylene (PP) and cis-polyisoprene (PIP) as substrates which can rapidly spread oxidative damage, the factors controlling the reaction of PFNs can be determined from CL and fluorescence as well as infra-red (IR) spectroscopy through the detection of oxidation products as measured by the carbonyl index. Matrix effects on the reactivity are demonstrated using a polyethylene-norbornene copolymer (TOPAS) as carrier for both PIP and the PFN and it is seen that the PFN is a radical scavenger only above Tg of the carrier. When PIP alone is oxidized, the PFN is an integrating sensor for free radical production under ambient conditions for up to twelve months while also stabilizing the polymer. Critically, it is thus able to determine the underlying rate of radical production in the oxidation induction period.

Chemiluminescence as a PDT light source for microbial control

The photodynamic therapy (PDT) is a combination of using a photosensitizer agent, light and oxygen that can cause oxidative cellular damage. This technique is applied in several cases, including for microbial control. The most extensively studied light sources for this purpose are lasers and LED-based systems. Few studies treat alternative light sources based PDT. Sources which present flexibility, portability and economic advantages are of great interest. In this study, we evaluated the in vitro feasibility for the use of chemiluminescence as a PDT light source to induce Staphylococcus aureus reduction. The Photogem® concentration varied from 0 to 75 μg/ml and the illumination time varied from 60 min to 240 min. The long exposure time was necessary due to the low irradiance achieved with chemiluminescence reaction at μW/cm 2 level. The results demonstrated an effective microbial reduction of around 98% for the highest photosensitizer concentration and light dose. These data suggest the potential use of chemiluminescence as a light source for PDT microbial control, with advantages in terms of flexibility, when compared with conventional sources.

NO x emission characteristics and aerodynamic structure of a self-recirculation type burner for small boilers

To meet the coming, more stringent NO x emission standards for small boilers, a self-recirculation type burner, in which a fresh air is injected through eight nozzles, arrayed peripherally around a liquid fuel-spray nozzle, while the hot burned gas is recirculated within the furnace and entrained into the injected air streams has been experimentally investigated. The flowfield has been determined with a PIV system and spatial distributions of NO x , temperature, O 2 and CO have been determined with use of chemi-luminescence, thermocouple, magnetic pressure type analysis, and non-dispersive infrared analysis, respectively. 2-D flame chemi-luminescence images have been obtained by an ICCD camera synchronized with the PIV system. Results show that the burned gas is recirculated in the furnace and successively entrained into the air streams. As a result, NO x emission is drastically decreased. In the present prototype burner, the amount of a recirculating gas entrained into the air streams attains 50% the fresh air by volume and the NO x level is decreased to 22 ppm from its original value of 108 ppm without recirculation. Further measurements show that besides the recirculating flow outside the air nozzles, another recirculating flow is induced around the center axis inside the injected air streams. Combustion is stabilized around this inner recirculation zone. With an increase in the air flow rate while keeping the spraying fuel flow rate constant, this inner recirculation zone expands and its centre approaches the fuel nozzle. The evaporation of liquid fuel is promoted and a blue flame zone is established. The NO x level is further reduced to 18 ppm when the air excess ratio is increased to 1.6. Thus, the present, simple device of self-recirculation type burner can successfully reduce NO x emission without great cost and space.

Comparison of chemiluminescence and flow cytometry in the estimation of reactive oxygen and nitrogen species in human semen

To determine the relative contribution of different cell types in washed sperm to the overall intracellular production of H(2)O(2) and peroxynitrite. Prospective study. University hospital. Thirty-one fertile volunteers and 166 men undergoing fertility assessment were included. Aliquots of sperm suspension in phosphate-buffered saline solution were used for the reactive oxygen species (ROS) detection by chemiluminescence and for the detection of H(2)O(2) and peroxynitrite by flow cytometry, with use of specific fluorescent probes, carboxy-2',7'-dichlorodihydrofluorescein diacetate dye for H(2)O(2) and dihydrorhodamine 123 for peroxynitrite. Gated analysis determined the relative contribution of spermatozoa, leukocytes, and "other round cells." Simultaneous estimates of global ROS production assessed by chemiluminescence assay compared with flow cytometric measurements. The estimates of ROS with use of chemiluminescence positively correlated with the estimates of H(2)O(2) (r = 0.53) and peroxynitrite (r = 0.62) as assessed with flow cytometry. H(2)O(2) and peroxynitrite were measurable also in samples in which chemiluminescence did not detect measurable values. Increased production of H(2)O(2) by one cell type was associated with a relative increase in its peroxynitrite production. The levels of ROS production measured by chemiluminescence and flow cytometry were related. Each cell type in semen contributed differently to the global intracellular levels of H(2)O(2) and peroxynitrite.

Lifetime Prediction of Rubber Using the Chemiluminescence Approach and Isoconversional Kinetics

A common scepticism towards the application of many materials in art or in conservation-restoration results from the fact that their long-term stability is unknown and difficult to predict. In the present study we report on a new approach of kinetic analysis of the oxidation reactions of natural rubbers with and without stabiliser in an oxygen atmosphere at moderate temperatures using chemiluminescence measurements carried out on newly developed instrumentation. The kinetic parameters of the oxidation process, calculated from the chemiluminescence signals by means of the differential isoconversional method of Friedman, were subsequently applied to the simulation of the rubber aging using different temperature profiles. The results are a first step towards the use of chemiluminescence to characterise the oxidative aging of rubber and predicting the lifetime of rubber items.

Chemiluminescent and bioluminescent assays as innovative prospects for mycotoxin determination in food and feed

Mycotoxin contamination of food and feedstuffs is among the top priorities for human and animal safety. The currently used techniques for mycotoxin determination, either chromatography or ELISA, are unsuitable for routine in-field assessment. There is an urgent need for other accurate, simple and cost-effective techniques that can be used as a screening tool for a rapid estimation of mycotoxin contamination in commodity lots. This paper reviews the literature on the use of chemiluminescence (CL) and bioluminescence (BL) assays for direct or indirect mycotoxin assessment. The chemiluminescence immunoassays, adenosine triphosphate (ATP) bioluminescence and bioassays are reviewed and their advantages and limitations discussed. These techniques used in food testing and the pharmaceutical industry offer promise as rapid techniques for mycotoxin determination. Chemiluminescence and bioluminescence bioassays are the most innovative alternatives to the conventional techniques used for mycotoxin determination in food and feed.

Real time endoscopic imaging of oxyradical generation in pig stomach during ischemia-reperfusion.

Oxygen-free radicals generation is considered to be a major cause of gastric injury during reperfusion. Chemiluminescence has been used to assess real-time free radical release on the surface of isolated organs. To evaluate the combined use of chemiluminescence and gastroendoscopy techniques and to assess the real-time production of free radicals during ischemic damage of the gastric wall in an animal model. For the experiment, an optical junction was set up between a fibroendoscope and a luminograph apparatus. Three pigs were submitted to gastrofibroendoscopy before, during and after 30 min of clamping of the coeliac artery. Under basal conditions, at the end of the ischemic phase and at the beginning of reperfusion, 1 mM of lucigenin, a specific superoxide enhancer, was injected in the left gastric artery of the animal. The endoscopic live images and chemiluminescence emission were recorded and successively superimposed to measure rate and spatial distribution of photon emission (photons/s). Free radical production was not observed under basal conditions or during the ischemic phase, but significantly increased during reperfusion reaching a maximum peak after 15 min (0.6+/-0.2 photons x 10(5)/s) and decreased progressively thereafter. The superimposition of live and chemiluminescence images allowed the determination of the regional production rate and distribution of photons. Preliminary observations, in an animal model, on an innovative imaging system which allows the visualization of rate and spatial distribution of reactive oxygen species formation are presented. This new endoscopic technique could be useful for the assessment of oxidative gastric mucosal injury in several gastric diseases; however, further studies remain necessary to determine the applicability of this technique in humans.

Chemiluminescence and fluorescence for monitoring the photooxidation of an UV-cured aliphatic polyurethane-acrylate based adhesive

The photooxidation of an UV-cured polyurethane-acrylate adhesive, has been monitored through the use of chemiluminescence and fluorescence techniques. Chemiluminescence analysis shows early stages of photooxidation in the adhesive when there is neither loss or change in the physical and chemical properties of the material. Moreover, fluorescent probes incorporated into the adhesive formulation have been found to be very useful to detect the first oxidation species. Quenching of fluorescence follows the same kinetics as the chemiluminescence increase during UV-exposure. Two fluorescent probes, p-dimethylamino salicylic acid and 2′,7′-difluorfluorescein, were sensitive to the formation of oxidation products. Therefore, good correlations between fluorescence and chemiluminescence were established. We conclude that the fluorescence emission from extrinsic probes can be used as a valuable method to analyse photooxidation from the initial stages.

Increased vascular superoxide production via NADH/NADPH oxidase activation in spontaneously hypertensive rats

This study was designed to test the hypothesis that stimulation of nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase is involved in increased vascular superoxide anion ( · O2−) production in spontaneously hypertensive rats (SHR). The study was performed in 16-week-old and 30-week-old normotensive Wistar-Kyoto rats (WKY16 and WKY30, respectively) and in 16-week-old and 30-week-old SHR (SHR16 and SHR30, respectively). In addition, 16-week-old SHR were treated with oral irbesartan (average dose 20 mg/Kg per day) for 14 weeks (SHR30-I). Aortic NADH/NADPH oxidase activity was determined by use of chemiluminescence with lucigenin. The expression of p22phox messenger RNA (mRNA) was assessed by competitive RT-PCR. Vascular responses to acetylcholine were determined by isometric tension studies. Aortic wall structure was studied determining the media thickness and the cross sectional area by morphometric analysis. Whereas systolic blood pressure (SBP) was significantly increased in the two groups of hypertensive animals compared with their normotensive controls, no differences were observed in SBP between SHR30 and SHR16. No other differences in the parameters measured were found between WKY16 and SHR16. In SHR30 compared with WKY30, we found significantly greater p22phox mRNA level, NADH/NADPH-driven · O2− production, media thickness and cross sectional area, and an impaired vasodilation in response to acetylcholine. Treated SHR had similar NADH/NADPH oxidase activity and p22phox expression as the WKY30 group. The vascular functional and morphologic parameters were improved in SHR30-I. These findings suggest that an association exist between p22phox gene overexpression and NADH/NADPH overactivity in the aorta of adult SHR. Enhanced NADH/NADPH oxidase-dependent · O2− production may contribute to endothelial dysfunction and vascular hypertrophy in this genetic model of hypertension.