Changes In GSH Concentrations Research Articles

Development of a fast fluorescent probe for sensitive detection of glutathione in 100 % aqueous solution and its applications in real samples, oxidative stress model and ferroptosis model

Glutathione (GSH) plays a crucial role in several physiological processes, including anti-oxidation and heavy metal detoxification. GSH is produced endogenously in the human body and can also be obtained through diet. The development of fast, highly sensitive, and multi-application fluorescent probes remains a challenging task. In this study, we have designed and synthesized a coumarin-based fluorescent probe (NFRF) for the sensitive and rapid detection of GSH in 100 % aqueous solution. By loading probe NFRF on the filter paper, the real-time visual detection of GSH is achieved in both daylight and fluorescence modes, providing a convenient, economical and rapid on-site detection tool. Probe NFRF could be used for the detection of GSH in real samples, with recoveries rates of 81.74 %–115.12 %. Notably, the probe imaged changes in GSH concentrations in oxidative stress environments and during ferroptosis. This work provides a prospective method for GSH detection in food and complex biological systems.

Protective Role of Gallic Acid with Rutin or Quercetin on Testicular Glutathione and Histopathology in Rats Exposed to Busulfan

Busulfan (BUS) is an alkylating agent used in chemotherapy that induces oxidative stress and testicular damage. This study investigates the protective effects of co-administering Gallic Acid (GAL) with Rutin (RUT) or Quercetin (QUE) against BUS-induced reductions in testicular glutathione (GSH) in Wistar rats. Thirty-two (32) male Wistar rats were randomly divided into four groups: control, BUS only, BUS+GAL+RUT, and BUS+GAL+QUE. Over a 56-day treatment period, the rats were assessed for changes in GSH concentration and testicular histopathology. GSH levels were measured to evaluate oxidative stress, while histological evaluations were performed to assess spermatogenic recovery. BUS administration significantly reduced GSH concentration in the testis, indicating oxidative stress. Co-administration of GAL+RUT or GAL+ QUE reversed this decrease, restoring GSH levels to near-control values. Although there were no significant changes in testicular and body weight across groups, the histopathological analysis showed that GAL+QUE improved spermatogenesis recovery more effectively than GAL+RUT. Additionally, GAL+RUT exhibited more mature germ cells and potential for testicular repopulation. The co-administration of GAL+RUT or GAL+QUE effectively mitigates BUS-induced oxidative stress in rat testes, with GAL+QUE demonstrating superior recovery in spermatogenic function. These findings suggest that incorporating these flavonoid combinations could help reduce chemotherapy-induced testicular damage.

In-vivo two-photon visualization and quantitative detection of redox state of cancer.

Glutathione (GSH), the most common and abundant antioxidant in the body, is particularly concentrated in cancer cells (2-10 mM). This concentration is approximately 1000 times that of normal cells, making GSH a specific tumor marker. Overexpression of GSH is critical for mapping the redox state of cancer cells. However, there are few probes and detection methods responsive to GSH that can quantitatively visualize GSH in vivo in two-photon excitation fluorescence (TPEF) imaging mode. The experimental results show that TPEF-GSH could not only target GSH in tumors, but also establish the quantitative relationship between TPEF signal and GSH concentration. We explored the optimal two-photon excitation wavelength of TPEF-GSH, the optimal cell incubation duration with TPEF-GSH, the best imaging time point for GSH in cells, and the quantitative relationship between the TPEF signal and the changes in GSH concentrations. In zebrafish embryo and zebrafish experiments, the ratiometric value of TPEF-GSH increased with the decrease of GSH concentration. Microinjection and co-incubation were used to verify whether the ratiometric value could quantify endogenous GSH in tumor-bearing zebrafish, and the obtained GSH levels were 4.66 mM and 5.16 mM, respectively. The ratio TPEF probe could accurately visualize and quantify GSH in vivo, reflecting the redox status of the tumor. The design of the ratiometric molecular probe provides a reliable strategy for the development of TPEF nanoprobe in vivo. In this article, a new GSH sensitive molecular probe, TPEF-GSH, has been developed with good specificity and sensitivity. TPEF-GSH was successfully used to image cancer cells in vitro and tumor-bearing zebrafish in vivo, and to further detect GSH levels.

Evaluating the Protective Effects of Mitochondrial Glutathione on Cerebral Ischemia/Reperfusion Injury via Near-Infrared Fluorescence Imaging

Cerebral ischemia/reperfusion (I/R) is common and intractable in the clinic, associated with the outburst of reactive oxygen species (ROS) in mitochondria. Although numerous research studies have been conducted to prove the protective-effect roles of glutathione (GSH) in this event, the changes in GSH concentrations in living cells remain largely unexplained, and there is scarce evidence by fluorescence imaging for its roles. Herein we have designed and synthesized two distinctive "off-on" near-infrared (NIR) fluorescent probes BCy-SeSe and BCy-SS based on a new fluorophore BCy-Keto for specific response to mitochondrial GSH changes during the cerebral I/R process. Both of them exhibit powerful targeting capability in mitochondria and excellent photophysical properties toward endogenous GSH with high selectivity and sensitivity. In contrast to BCy-SS, BCy-SeSe was screened for biological application on account of its faster response rate. We have utilized BCy-SeSe to real-time image GSH during the cerebral I/R process in living cells and the mice focal cerebral ischemia model (middle cerebral artery occlusion, MCAO), and these intensive studies revealed that low GSH levels were associated with aggravation of apoptosis and cerebral infarction. Pretreatment with GSH synthase inhibitor aggravates damage while GSH-ester alleviates damage, confirming that GSH is effective on the cerebrum for protection from I/R. All the results demonstrated that the probes were powerful tools for investigating mitochondrial GSH during the I/R process in living cells and in vivo.

MEGA-PRESS and PRESS measure oxidation of glutathione in a phantom

PurposeInvestigate the possibility of measuring changes in glutathione (GSH) concentration using the MRS PRESS and MEGA-PRESS sequences by tracking the natural oxidation of GSH, and to examine the accuracy of the two methods. Methods122 GSH edited MEGA-PRESS and PRESS acquisitions were acquired on a “braino” based phantom +3.0 mM GSH during a period of 11 days. All spectra were analyzed in LCModel. (The MEGA-PRESS data were first preprocessed in Matlab). Degradation curves were modeled. A one year follow-up on the same phantom and measurements from a similar phantom without GSH and one pure GSH phantom were also included. ResultsBoth MEGA-PRESS and PRESS showed degradation of the measured GSH signal. Modeling the exponential decay of the GSH signal in MEGA-PRESS and PRESS gave for t = 0; 2.9 i.u. for MEGA-PRESS and 2.3 i.u. for PRESS. As t increased, the GSH concentration converged to zero for MEGA-PRESS but not for PRESS (0.7 i.u.). GSH for the one year follow up were 0.0 i.u. for MEGA-PRESS and 0.6 i.u. for PRESS. Similar phantom without GSH yielded 0.0 i.u. for both MEGA-PRESS and PRESS. ConclusionIt is possible to measure changes in GSH concentration in a phantom using both PRESS and MEGA-PRESS techniques, however the PRESS spectrum appears to include oxidized GSH (GSSG). In addition, GSH edited MEGA-PRESS measurement gives more precise values at lower GSH concentrations.

Glutathione as an antioxidant marker: determination of glutathione concentration in the breast muscles and liver of broilers supplemented with different selenium sources

The aim of the study was to determine the influence of different selenium sources on antioxidant properties. The glutathione (GSH) concentration and glutathione peroxidase (GPx) activity were measured in the breast muscles and liver of 60 one-day-old broiler chickens. Another goal was to compare these indices with the weights of individual tissues and the live weight of broilers. The broilers were divided into 4 groups according to the selenium source: group 1 (control), group 2 (selenized yeast), group 3 (selenomethionine), group 4 (sodium selenite). Treatment groups were supplemented with 0.2 mg of additional selenium/kg. No significant changes in the hepatic GSH concentrations (P> 0.05) were found in the experimental groups compared to control. Significantly higher GSH concentration (P< 0.05) was found in breast muscles of broilers in group 4 (sodium selenite) compared to control. However, no positive effect of selenium supplementation in the form of sodium selenite was observed. The differences in the GPx activity in breast muscles and liver between the experimental groups and the control group were not significant (P> 0.05). No significant differences were recorded in the experimental groups compared to control in relation to the GSH concentration and GPx activity measured in the tissues. A significantly positive correlation was noted between mean GPx activity in breast muscle and breast muscle weight (P< 0.01; r = 0.3790) and live weight (P< 0.05; r = 0.2690). Although changes in the GSH concentration and GPx activity were recorded in some experimental groups, the selected dose of additional selenium appeared to be too low to affect these concentrations and the antioxidant defence system.

Sensitivity and specificity of human brain glutathione concentrations measured using short-TE (1)H MRS at 7 T.

Although the MR editing techniques that have traditionally been used for the measurement of glutathione (GSH) concentrations in vivo address the problem of spectral overlap, they suffer detriments associated with inherently long TEs. The purpose of this study was to characterize the sensitivity and specificity for the quantification of GSH concentrations without editing at short TE. The approach was to measure synthetically generated changes in GSH concentrations from in vivo stimulated echo acquisition mode (STEAM) spectra after in vitro GSH spectra had been added to or subtracted from them. Spectra from five test subjects were synthetically altered to mimic changes in the GSH signal. To account for different background noise between measurements, retest spectra (from the same individuals as used to generate the altered data) and spectra from five other individuals were compared with the synthetically altered spectra to investigate the reliability of the quantification of GSH concentration. Using STEAM spectroscopy at 7 T, GSH concentration differences on the order of 20% were detected between test and retest studies, as well as between differing populations in a small sample (n = 5) with high accuracy (R(2) > 0.99) and certainty (p ≤ 0.01). Both increases and decreases in GSH concentration were reliably quantified with small impact on the quantification of ascorbate and γ-aminobutyric acid. These results show the feasibility of using short-TE (1)H MRS to measure biologically relevant changes and differences in human brain GSH concentration. Although these outcomes are specific to the experimental approach used and the spectral quality achieved, this study serves as a template for the analogous scrutiny of quantification reliability for other compounds, methodologies and spectral qualities.

A longitudinal proton magnetic resonance spectroscopy study investigating oxidative stress as a result of alcohol and tobacco use in youth with bipolar disorder

Alcohol and tobacco have been suggested to be “aggravating factors” for neuroprogression in bipolar disorder (BD), however the impact of these substances on the underlying neurobiology is limited. Oxidative stress is a key target for research into neuroprogression in BD and in accordance with this model, our previous cross-sectional studies have found that risky alcohol and tobacco use in BD is associated with increased oxidative stress, investigated via in vivo glutathione (GSH) measured by proton magnetic resonance spectroscopy (1H-MRS) in the anterior cingulate cortex (ACC). What remains unknown is whether the negative impact on GSH levels can be modified as a result of limiting alcohol and tobacco use.Thirty BD patients were included in the study. 1H-MRS and tobacco and alcohol measures were conducted at baseline and follow-up assessments (15.5±4.6 months apart). Pearson׳s correlations were performed between percentage change in GSH concentration and changes in alcohol/tobacco use. Regression analyses were then conducted to further explore the significant correlations. An increase in GSH was associated with a decrease in alcohol consumption (r=−0.381, p<0.05) and frequency of tobacco use (−0.367, p=0.05). Change in alcohol consumption, tobacco use and age were significant predictors of change in GSH concentration (F (3, 26)=3.69, p<0.05). Due to the high comorbidity of alcohol and tobacco use in the sample, the individual effects of these substances on GSH levels could not be determined.This study offers longitudinal evidence that changing risky drinking patterns and tobacco use early in the course of BD is associated with improvements in antioxidant capacity, and therefore may be specific targets for early intervention and prevention of neuroprogression in BD.

Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe.

Glutathione (GSH) plays an important role in maintaining redox homeostasis inside cells. Currently, there are no methods available to quantitatively assess the GSH concentration in live cells. Live cell fluorescence imaging revolutionized the field of cell biology and has become an indispensable tool in current biological studies. In order to minimize the disturbance to the biological system in live cell imaging, the probe concentration needs to be significantly lower than the analyte concentration. Because of this, any irreversible reaction-based GSH probe can only provide qualitative results within a short reaction time and will exhibit maximum response regardless of the GSH concentration if the reaction is completed. A reversible reaction-based probe with an appropriate equilibrium constant allows measurement of an analyte at much higher concentrations and, thus, is a prerequisite for GSH quantification inside cells. In this contribution, we report the first fluorescent probe—ThiolQuant Green (TQ Green)—for quantitative imaging of GSH in live cells. Due to the reversible nature of the reaction between the probe and GSH, we are able to quantify mM concentrations of GSH with TQ Green concentrations as low as 20 nM. Furthermore, the GSH concentrations measured using TQ Green in 3T3-L1, HeLa, HepG2, PANC-1, and PANC-28 cells are reproducible and well correlated with the values obtained from cell lysates. TQ Green imaging can also resolve the changes in GSH concentration in PANC-1 cells upon diethylmaleate (DEM) treatment. In addition, TQ Green can be conveniently applied in fluorescence activated cell sorting (FACS) to measure GSH level changes. Through this study, we not only demonstrate the importance of reaction reversibility in designing quantitative reaction-based fluorescent probes but also provide a practical tool to facilitate redox biology studies.

Study of interrelations between resistance to cisplatin and composition of low molecular weight thiols in murine leukemia L1210 cell lines

Cis -dichlorodiammineplatinum (II), commonly known as cisplatin, is a widely used anticancer drug. However, the therapeutic efficacy of the drug is limited due to various dose-limiting side effects and development of acquired resistance. The resistance of malignant cells to cisplatin may be connected to elevated concentration of cellular thiols. To verify this hypotheses, we compared the concentrations of low weight cellular thiols, metallothionein (MT) and glutathione (reduced, GSH and oxidized, GSSG) and also the metal-binding properties of MT in the two cell lines, known to be resistant (L1210R) or sensitive (L1210S) to cisplatin. It was established that R-cells were characterised by hi­gher concentrations of MTs and GSH, higher ratio of copper in the composition of MTs in comparison to zinc than S-cells. The treatment by cisplatin provoked the decrease of the GSSG concentration only in the S-cells without the changes in GSH concentration. Hence, R-cells insensitivity to cisplatin can be related to higher levels of MTs and GSH. Reported for the first time peculiar metal composition of MTs in R-cells can also give an advance to these cells by particular oxidizing properties of copper-MT. These specific characteristics of thiols in malignant cells could be useful for the indication of cisplatin resistance. Keywords: cisplatin, resistanse, metallothionein, glutathione, copper.

Selective detection of endogenous thiols using microchip-based flow analysis and mercury/gold amalgam microelectrodes.

This paper describes the fabrication and characterization of thin-layer mercury/gold amalgam microelectrodes and their integration with microchip-based flow injection analysis. This microchip platform allows on-chip injection and lysis of erythrocytes followed by selective detection of intracellular glutathione (GSH) at low potentials. The thin-layer gold microelectrodes were amalgamated by electrodeposition of mercury. The electrodes produced a linear response for both GSH and cysteine in flow injection analysis studies utilizing both off-chip and on-chip injection. Comparative experiments using diamide and on-chip injection were performed to demonstrate the ability of the microchip device to detect changes in GSH concentration. Finally, rabbit erythrocyte samples (2% hematocrit) were injected and lysed on-chip and the amount of GSH detected corresponded to 312 amol/cell, which is in agreement with previously reported values. The selectivity, short time between injection and detection (approximately 5 s), and the continuous introduction of sample to the on-chip injector should enable the study of dynamically changing systems such as the glutathione redox system found in erythrocytes.

Protective effects of ethyl pyruvate treatment on paraquat-intoxicated rats

Although, numerous studies have attempted to reduce the oxygen radical injury induced by the antioxidants in paraquat intoxication, these antioxidant therapies have showed few survival benefits. Ethyl pyruvate (EP) may function as an effective scavenger of oxygen radicals, an anti-inflammatory agent and an energy source in many ischemia reperfusion models. The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of EP on the lung and the liver tissues in paraquat-intoxicated rats. Rats were randomly given either a low (2 mg/kg i.p.) or high (40 mg/kg i.p.) EP dose, 30 min before or 1 h after paraquat (50 mg/kg i.p.) administration, and subsequently killed at 6 and 24 h. Glutathione (GSH) and malondialdehyde (MDA) levels of the lungs and the livers, and plasma nitric oxide (NO) concentrations were measured. Pretreatment of EP significantly decreased the MDA level in the lung and the liver tissues. EP also significantly decreased plasma NO concentrations at 6 h. EP pretreatment, however, failed to show significant change in GSH concentration. In post-treatment of EP, MDA levels in the lung tissue and plasma NO levels were significantly decreased. In conclusion, EP decreased the lipid peroxidation and seemed to exert an anti-inflammatory action in the paraquat intoxication rat model.

Glutathione and glutathione-dependent enzymes in sperm and seminal plasma from infertile men

Both glutathione (GSH) and glutathione-dependent enzymes- glutathione peroxidase (GPx) and glutathione-S-transferase (GST) play an important role in antioxidant scavenger system. GSH acts directly with hydrogen peroxide, superoxide anion, hydroxyl and alkoxyl radicals. Due to its structure GSH easily gives away a proton. GSH is used by GPx and GST for restoration of damaged biomolecules. The objective of our study was to determine the levels of GSH, GPx and GST in partners of couples enrolled in ART clinic. Prospective study. A total of 91 patients were grouped according to their semen characteristics: group 1: normozoospermic (n = 40) which served as the control; group 2: asthenozoospermic (n = 30) and group 3: teratozoospermic (n = 21). Semen analysis was done according to the WHO guidelines. Total GSH and levels of GPx and GST were measured in spermatozoa and seminal plasma colorimetrically. GSH was measured by 5, 5'-dithio-bis-2-nitrobenzoic acid method and read at 412 nm. The activity of GPx was measured by the change in GSH concentration before and after incubation with glutathione and measuring the absorbance at 412 nm. GST was detected at 340 nm by measuring total GST activity by conjugation of 1-chloro-2,4-dinitrobenzene with reduced glutathione. Protein concentration was measured microbiuret method. Antioxidant levels in the 3 groups are shown in the Table.Tabled 1Values are mean ± SE. a<0.05 and b<0.01 in each group by Wilcoxon test Open table in a new tab Values are mean ± SE. a<0.05 and b<0.01 in each group by Wilcoxon test Antioxidant levels are significantly reduced both in spermatozoa and seminal plasma of astheno- and teratozoospermic men. This may be related to the oxidative stress related pathophysiology of infertility in these men.

A focus on cell proliferation and death

As you have noticed, the Editorial Office has made major efforts to redesign and improve the journal appearance and contents. This has included the simplification of the submission formats and the introduction of Commentaries to highlight important manuscripts. I believe that this will bring an increased visibility of interesting manuscripts to a broader scientific audience. The September issue starts with another novelty: focusing on a specific topic in a given issue. As these papers are not invited but are regular submissions, focusing on certain topics will depend on the manuscripts we have “in-house.” The September issue presents a collection of manuscripts that are loosely related to DNA analysis, cell proliferation, and death. It starts with an exciting review by the group of Darzynkiewicz (page 648) on ATM activation and histone H2AX phosphorylation to determine DNA damage by cytometric tools. The review elegantly shows the value of flow- and image-cytometry in studying factors that affect DNA repair and explore the linkage between DNA damage, cell cycle checkpoints, and initiation of apoptosis. King et al. (page 668) investigated apoptosis induction in Jurkat cells using three different flow cytometric methods: cytochrome c release, loss of mitochondrial cardiolipin, and decrease of mitochondrial membrane potential. They demonstrated that in their model system, cytochrome c release is a good marker but underestimates the fraction of apoptotic cells. Hollier et al. (page 675) evaluated two assays for apoptosis detection in clinical samples. They proposed two independent novel assays that enable determination of not only the major apoptosis pathways but also the cell types affected. Shi et al. (page 686) investigated the influence of over-expression of glutamate-cysteine ligase (GCL) on the resistance of single-strand breaks to peroxide treatment in two cell lines. Their study yielded the important finding that genetic factors affecting GCL expression have an impact on DNA single-strand breaks and thus affect susceptibility towards cancer. In the study of Slaninova et al. (page 700), quaternary benzo[c]phenanthridine binding to DNA of viable cells was demonstrated. Because of their fluorescent characteristics, the nuclear architecture, chromosomes, and apoptotic fragments could be visualized in fluorescence microscopy and flow cytometry. The authors also stated that a cell cycle analysis would be possible by using the alkaloid macarpine. Intracellular Glutathione (GSH) is attracting attention in the investigation of many diseases due to its role in cell protection. Hamilton et al. (page 709) focused on rapid assessment of GSH levels in clinical settings. Using three different drug treatments they demonstrated that the changes in GSH concentration could be detected semi-quantitatively by CM-SNARF. Quantitation of DNA content and cell cycle are prerequisites for the analysis of changes in the cell cycle. Wang and Huang (page 716) proposed a mixture-model classification for DNA content analysis. They demonstrated in a model system the sensitivity of their approach for detecting cell cycle differences in mixed populations. Lin et al. (page 724) showed a multi-model approach for quantitative studies of 3D confocal microscope images. With their method, nuclear segmentation and classification of heterogenous populations of cell nuclei—like in tissues with multiple cell types and different nuclear features—could be analyzed simultaneously. Since its early years, the journal Cytometry stood out by publishing groundbreaking technologies like DNA flow cytometry of fresh-frozen (1) or paraffin embedded tissues (2), both being standard methods today. Over the last few years new methods, in particular analysis of apoptosis (3), have been proposed. Such novel techniques are released regularly in our journal and obtain the status of standard protocols. These papers belong to the most cited ones in Cytometry. As an example, the paper by Vindelov et al. (1) has been cited over 1,500 times. Tissue Cytometry was introduced in Cytometry Part A as an alternative method to perform quantitative analysis in sectioned material (4). Supporting this concept Mosch et al. (5) proposed quantitative DNA cell cycle analysis of brain sections by Slide Based Cytometry (SBC). Recently, the group clearly demonstrated that SBC analyses of the cell cycle distribution are equal to other independent molecular biological methods (6). This highly emphasizes the great relevance of quantitative imaging and automated analysis of the cell cycle in tissues. The journal Cytometry was in the past and will be in the future an important source for biomedical research and novel technologies for determining cell cycle and death in a quantitative fashion as demonstrated by the manuscripts of this issue. I hope to see your exciting research sent to our journal in the future.

Induction of glutamate-cysteine ligase (γ-glutamylcysteine synthetase) in the brains of adult female mice subchronically exposed to methylmercury

Methylmercury (MeHg) is widely known for its potent neurotoxic properties. One proposed mechanism of action of MeHg relates to its high affinity for sulfhydryl groups, especially those found on glutathione (GSH) and proteins. Previous studies have shown that acute MeHg exposure results in an increase in the mRNA for the rate-limiting enzyme in GSH synthesis, glutamate-cysteine ligase (GLCL) (also known as γ-glutamylcysteine synthetase). In this study, we evaluated the effects of subchronic (12-week) MeHg exposure at 0, 3 or 10 ppm in the drinking water on GSH levels, GLCL catalytic (GLCLC) and regulatory subunit mRNA and protein levels, and GLCL activity in brain, liver and kidney tissue of C57Bl/6 female mice. Contrary to previous findings in rats, there were no changes in GSH concentration in any of the tissues examined. However, there was an increase in GLCLC protein in the brain, which was accompanied by a 30% increase in GLCL activity. We conclude that up-regulation of GSH synthetic capacity in the brains of mice is a sensitive biomarker of subchronic MeHg exposure.

Increased cerebral free radical production during thiamine deficiency

Concentration of reactive oxygen species (ROS) and the antioxidant glutathione (GSH) was measured in thalamus and cortex after 13 and 14 days of pyrithiamine-induced thiamine deficiency (PTD) in the rat. The concentration of ROS was significantly elevated in thalamus and cortex on day 14 when righting reflexes were absent and spontaneous seizures occurred. No significant changes in GSH concentration were observed in thalamus or cortex on either day of treatment. These findings suggest that increased formation of free radicals occurs during the more acute symptomatic stage of thiamine deficiency and may contribute to the structural damage described in this model of Wernicke's encephalopathy.

Changes in tissue glutathione levels in the cichlidoreochromis aureus(steindachner) following long term exposure to mercury, cadmium and lead

Oreochromis aureus was exposed to the metals cadmium, mercury and lead individually, or as mixtures of two metals, for 140 days. At least 2 different concentrations of each metal were used. Seven or eight different fish tissues were analysed for reduced glutathione (GSH) content at the end of the exposure period with the objective of identifying tissues which would give a characteristic change in GSH concentration in response to heavy metal pollution. Significant changes observed in tissue GSH concentrations were all increases, with few exceptions. The most commonly occurring response was an increase in kidney GSH content. This always occurred following exposure to cadmium, at all concentrations and in the persence of other metals. Therefore elevated renal GSH levels might serve as indicatiors of cadmium exposure.

Concentration-activity profile of the modulation of cyclooxygenase product formation by reduced glutathione in microsomal fractions from the goat lung

Age-related changes in pulmonary formation of arachidonic acid (AA) metabolites are thought to play an important role in regulating cardiopulmonary function. This study addresses the potential role of reduced glutathione (GSH) in modulating cyclooxygenase product formation in the developing lung. Prostaglandin H 2 (PGII 2) metabolism was studied in microsomal fractions isolated from the lungs of unventilated fetal, neonatal and adult goats. GSH-dependent PGH 2 to PGE 2 isomerase activity in microsomal fractions from the perinatal (fetal and neonatal) goat lung was not saturable with respect to GSH and can respond to changes in GSH concentration over the range of 0.01 to 30 mM, which encompasses the full range the intracellular GSH levels reported in the literature. However, in fractions from the adult, a lower rate of PGE 2 formation is observed at higher GSH concentrations. In addition, the tissue levels of GSH exhibited developmental stage-related differences with fetal being higher than neonatal or adult. The present observations may have physiologic relevance, in that decreases in pulmonary GSH levels after birth may contribute to decreases in plasma PGE 2 levels by decreasing pulmonary PGE 2 synthesis, thereby contributing to closure of the ductus arteriosus; conversely, increased GSH levels associated with hyperoxia may contribute to persistence of ductal patency. Formation of 6-keto-PGF 1 α and of TXB 2 (the stable metabolites of prostacyclin and TXA 2) was decreased when PGE 2 formation was increased by GSH activation of PGE 2 isomerase in fractions isolated from all three developmental stages. A similar pattern of product formation was observed when AA was employed as substrate. These data suggest the possibility that changes in GSH concentration may modulate eicosanoid formation in cells that contain GSH-dependent PGE 2 isomerase, as well as either or both prostacyclin or thromboxane synthase(s).

Alcohol-induced congestive cardiomyopathy in adult turkeys: effects on myocardial antioxidant defence systems.

The effects of chronic intake of dietary alcohol upon left ventricular function, activities of myocardial antioxidant enzymes, reduced glutathione (GSH) content and lipoperoxidation (measured as the formation of diene conjugates and lipid-soluble fluorescence) were studied in adult domestic Nicholas turkeys. The non-invasive evaluation of left ventricular function by echocardiography revealed an impaired contractile function (the calculated fractional shortening values were 31.1 +/- 4.1% in the alcoholic group and 38.8 +/- 4.4% in the controls) and dilatation of the heart in the alcoholic birds. The changes in the non-invasive parameters of the left ventricle indicate that the adult Nicholas turkey developed congestive cardiomyopathy secondary to the ingestion of ethanol. In the hearts of normal adult turkeys, high GSH content (2.39 +/- 0.25 mumol/g wet weight) and superoxide dismutase activity were found, as compared to other animals, indicating the relatively higher development of antioxidant defence systems. Compared to the controls, significant increases were noted for all the antioxidant enzymes investigated (superoxide dismutase, catalase and glutathione peroxidase) and a moderately significant decrease in the GSH content was found in the left ventricle of alcoholic birds. The changes in GSH concentration and antioxidant enzyme activities might indirectly indicate some involvement of free radicals in the pathogenesis of ethanol-induced myocardial lesion. However, the levels of in vivo lipoperoxidation in the alcoholic birds did not significantly vary from those of control turkeys. Based on these findings, it appears that the reactive oxygen radicals may play a less important role in the pathogenesis of alcohol-induced cardiomyopathy in turkeys--probably due to the higher development of myocardial antioxidant defence systems.