Intermittent hypoxia, brain glyoxalase-1 and glutathione reductase-1, and anxiety-like behavior in mice

Objective: Sleep apnea has been associated with anxiety, but the mechanisms of the sleep apnea-anxiety relationship are unresolved. Sleep apnea causes oxidative stress, which might enhance anxiety-like behavior in rodents. To clarify the apnea-anxiety connection, we tested the effect of intermittent hypoxia, a model of sleep apnea, on the anxiety behavior of mice. Methods: The rodents were exposed daily to 480 one-minute cycles of intermittent hypoxia to a nadir of 7±1% inspiratory oxygen fraction or to a sham procedure with room air. After 7 days, the mice from both groups were placed in an elevated plus maze and were video recorded for 10 min to allow analysis of latency, frequency, and duration in open and closed arms. Glyoxalase-1 (Glo1) and glutathione reductase-1 (GR1) were measured in the cerebral cortex, hippocampus, and striatum by Western blotting. Results: Compared to controls, the intermittent hypoxia group displayed less anxiety-like behavior, perceived by a statistically significant increase in the number of entries and total time spent in open arms. A higher expression of GR1 in the cortex was also observed. Conclusion: The lack of a clear anxiety response as an outcome of intermittent hypoxia exposure suggests the existence of additional layers in the anxiety mechanism in sleep apnea, possibly represented by sleepiness and irreversible neuronal damage.

Effects of 5-aminolevulinic acid (ALA)-containing supernatants from selected Rhodopseudomonas palustris strains on rice growth under NaCl stress, with mediating effects on chlorophyll, photosynthetic electron transport and antioxidative enzymes

Background: Rice is globally one of the most important food crops, and NaCl stress is a key factor reducing rice yield. Amelioration of NaCl stress was assessed by determining the growth of rice seedlings treated with culture supernatants containing 5-aminolevulinic acid (ALA) secreted by strains of Rhodopseudomonas palustris (TN114 and PP803) and compared to the effects of synthetic ALA (positive control) and no ALA content (negative control). Results: The relative root growth of rice seedlings was determined under NaCl stress (50 mM NaCl), after 21 d of pretreatment. Pretreatments with 1 μM commercial ALA and 10X diluted culture supernatant of strain TN114 (2.57 μM ALA) gave significantly better growth than 10X diluted PP803 supernatant (2.11 μM ALA). Rice growth measured by dry weight under NaCl stress ordered the pretreatments as: commercial ALA N TN114 N PP803 N negative control. NaCl stress strongly decreased total chlorophyll of the plants that correlated with non-photochemical quenching of fluorescence (NPQ). The salt stress also strongly increased hydrogen peroxide (H2O2) concentration in NaCl-stressed plants. The pretreatments were ordered by reduction in H2O2 content under NaCl stress as: commercial ALA N TN114 N PP803 N negative control. The ALA pretreatments incurred remarkable increases of total chlorophyll and antioxidative activities of catalase (CAT), ascorbate peroxide (APx), glutathione reductase (GR) and superoxide dismutase (SOD); under NaCl stress commercial ALA and TN114 had generally stronger effects than PP803. Conclusions: The strain TN114 has potential as a plant growth stimulating bacterium that might enhance rice growth in saline paddy fields at a lower cost than commercial ALA.

Selected spices and their combination modulate hypercholesterolemia-induced oxidative stress in experimental rats

BACKGROUND: Effect of aqueous extracts of Allium sativum (garlic), Zingiber officinale (ginger), Capsicum fructensces (cayenne pepper) and their mixture on oxidative stress in rats fed high Cholesterol/high fat diet was investigated. Rats were randomly distributed into six groups (n = 6) and given different dietary/spice treatments. Group 1 standard rat chow (control), group 2, hypercholesterolemic diet plus water, and groups 3, 4, 5, 6, hypercholesterolemic diet with 0.5 ml 200 mg · kg-1 aqueous extracts of garlic, ginger, cayenne pepper or their mixture respectively daily for 4 weeks. RESULTS: Pronounced oxidative stress in the hypercholesterolemic rats evidenced by significant (p < 0.05) increase in MDA levels, and suppression of the antioxidant enzymes system in rat's liver, kidney, heart and brain tissues was observed. Extracts of spices singly or combined administered at 200 mg.kg-1 body weight significantly (p < 0.05) reduced MDA levels and restored activities of antioxidant enzymes. CONCLUSIONS: It is concluded that consumption of garlic, ginger, pepper, or their mixture may help to modulate oxidative stress caused by hypercholesterolemia in rats.

Antioxidant response and Lea genes expression under salt stress and combined salt plus water stress in two wheat cultivars contrasting in drought tolerance.

Two wheat cultivars, C306 and PBW343 contrasting in drought tolerance were compared for their antioxidant response and Lea genes’ expression under salt stress (SS) and combined stress (CS) of salt stress plus water stress during seedlings growth. The drought susceptible cultivar (PBW343) behaved different towards SS/CS than towards WS. It accumulated more dry masses in shoots, more ascorbate, had higher ascorbate to dehydroascorbate ratio, lesser dehydroascorbate, lesser malondialdehyde (MDA), more proline and higher antioxidant enzymes under SS than under WS. CS increased dry masses, ascorbate, ascorbate to dehydroascorbate ratio, antioxidant enzymes and decreased dehydroascorbate and MDA contents from levels under WS. The drought tolerant cultivar (C306) though showed higher levels of ascorbate, ascorbate to dehydroascorbate ratio, lower levels of dehydroascorbate, showed lesser dry biomasses in shoots, higher MDA and lesser ascorbate peroxidase and catalase activities under SS than under WS and these features were improved on combining WS with SS. All lea genes were induced under all stresses in both cultivars except Wrab17 in C306 only, was not induced under any stress. Eight Lea genes out of ten were induced higher under WS than SS in C306 but induced same in PBW343. Wdhn13 gene was higher salt-responsive than other lea genes in both cultivars.

Phytomodulatory potential of lycopene from Lycopersicum esculentum against doxorubicin induced nephrotoxicity.

An elevated level of serum urea and creatinine was observed in doxorubicin (DOX) treated animals indicating DOX-induced nephrotoxicity. Enhanced lipid peroxidation (LPO) in the renal tissue was accompanied by a significant decrease in the levels of reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CAT) activities. Administration of lycopene (LycT) extracted from tomato to DOX treated mice showed a significant reduction in serum creatinine and urea levels which were associated with significantly low levels of LPO and significantly enhanced level of GSH and related antioxidant enzymes activity (GPx, GR and CAT) when compared to DOX group. Histopathological analysis revealed severe damage in the renal tissue of DOX treated animals. However, animals pretreated with LycT were observed to have reduced damage. Thus, from present results it may be inferred that lycopene may be beneficial in mitigating DOX induced nephrotoxicity in mice.

Differential antioxidative response of tolerant and sensitive maize (Zea mays L.) genotypes to drought stress at reproductive stage.

The role of oxidative stress management was evaluated in two maize (Zea mays L.) genotypes — Parkash (drought-resistant) and Paras (drought-sensitive), subjected to drought stress during reproductive stage. Alterations in their antioxidant pools — glutathione (GSH) and ascorbic acid (AsA) combined with activities of enzymes glutathione reductase (GR), ascorbate peroxidase (APX), peroxidase (POX) and catalase (CAT) involved in defense against oxidative stress and stress parameters, namely chlorophyll (Chl), hydrogen peroxide (H2O2) and malondialdehyde (MDA) were investigated in flag leaves from silk emergence till maturity. The drought caused transient increase in GR, APX, POX and CAT activities in drought-tolerant genotype (Parkash) which decreased at later stages with the extended period of drought stress. However, in Paras, drought stress caused decrease in activities of GR and CAT from initial period of stress till the end of experiment, except for POX which showed slight increase in activity. A significant increase in GSH content was observed in Parkash till 35 days after silking (DAS), whereas in Paras, GSH content remained lower than irrigated till maturity. Parkash which had higher AsA and Chl contents, also showed lower H2O2 and MDA levels than Paras under drought stress conditions. However, at the later stages, decline in antioxidant enzyme activities in Parkash due to severe drought stress led to enhanced membrane damage, as revealed by the accumulation of MDA. Our data indicated that significant activation of antioxidant system in Parkash might be responsible for its drought-tolerant behavior under drought stress and helped it to cope with the stress up to a definite period. Thus, the results indicate that antioxidant status and lipid peroxidation in flag leaves can be used as indices of drought tolerance in maize plants and also as potential biochemical targets for the crop improvement programmes to develop drought-tolerant cultivars.

Effects of fluoride and ethanol administration on lipid peroxidation systems in rat brain.

Exposure to fluoride and excessive ethanol consumption has been identified as a serious public health problem in many parts of the world, including India. Thus, the effect of co-exposure to fluoride and ethanol for 3-6 weeks was studied on lipid peroxidation (LPO) and oxidative stress related parameters in the rat brain. After 3 weeks, co-treated animals showed 95% increase in LPO levels compared to control. However, the levels of reduced glutathione, total and protein thiols were decreased. These changes were accompanied by a decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase. Rats exposed to fluoride together with ethanol for 6 weeks resulted in 130% increase in LPO and decrease in the reduced glutathione levels. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase were reduced under these conditions. Brain histology revealed excessive lymphocytes, edema and spongeosis in the cortical region after six weeks of fluoride and ethanol treatment. These results suggest that exposure to fluoride together with ethanol enhances lipid peroxidation by affecting antioxidant defence systems in the rat brain.

Effect of aluminum exposure on superoxide and peroxide handling capacities by liver, kidney, testis and temporal cortex in rat.

Oxidant imbalance is one of the causative mechanisms of aluminum-induced neurotoxicity. In this study, we investigated aluminum-induced oxidant imbalance in non-neuronal tissues (liver, kidney and testis) and temporal cortex in rats. The differences in adaptations to superoxide and peroxide handling capacities (SPHC) of studied organs due to aluminum insult were also evaluated. Male Wistar rats were exposed to aluminum (10 mg/Kg body wt/day) for 4 weeks through orogastric intubation. Liver showed significant decrease in reduced glutathione level, while significant alteration in lipid peroxidation was observed in temporal cortex in aluminium-exposed animals. Superoxide dismutase activity was significantly altered in liver and temporal cortex and catalase activity significantly reduced in the liver due to aluminum exposure, while glutathione reductase and glutathione peroxidase activities were altered in all the tested organs. Among the organs, glutathione-independent SPHC was relatively higher in liver and kidney, while glutathione-dependent SPHC was relatively higher in testis and temporal cortex. As compared to control, aluminum-exposed rats demonstrated reduction in glutathione-dependent SPHC in temporal cortex and increment of the same in testis, while increment in glutathione-independent SPHC was observed in liver. In conclusion, aluminum-induced alteration in oxidant handling capacity could be the cause of oxidative stress both in the neuronal and non-neuronal tissues.

Influence of galactose cataract on erythrocytic and lenticular glutathione metabolism in albino rats.

Context: Glutathione depletion has been postulated to be the prime reason for galactose cataract. The current research seeks the prospect of targeting erythrocytes to pursue the lens metabolism by studying the glutathione system. Aims: To study the activity of the glutathione-linked scavenger enzyme system in the erythrocyte and lens of rats with cataract. Materials and Methods: Experiments were conducted in 36 male albino rats weighing 80 ± 20 g of 28 days of age. The rats were divided into two major groups, viz. experimental and control. Six rats in each group were sacrificed every 10 days, for 30 days. Cataract was induced in the experimental group by feeding the rats 30% galactose (w/w). The involvement of reduced glutathione (GSH) and the linked enzymes was studied in the erythrocytes and lens of cataractous as well as control rats. Statistical Analysis: Parametric tests like one-way ANOVA and Student's ‘t’ test were used for comparison. Correlation linear plot was used to compare the erythrocyte and lens metabolism. Results: Theconcentration of GSH and the activity of linked enzymes were found decreased with the progression of cataract, and also in comparison to the control. The same linear fashion was also observed in the erythrocytes. Conclusion: Depletion of GSH was the prime factor for initiating galactose cataract in the rat model. This depletion may in turn result in enzyme inactivation leading to cross-linking of protein and glycation. The correlation analysis specifies that the biochemical mechanism in the erythrocytes and lens is similar in the rat model.

Induction of oxidative stress by restraint stress and corticosterone treatments in rats.

Chronic exposure to psychological stress in humans and restraint stress in experimental animals results in increased oxidative stress and resultant tissue damage. To study the contribution of stress hormones towards stress-induced oxidative processes in the brain, we investigated the response of important free-radical scavenging enzymes toward chronic administration of two doses of corticosterone (low dose: 10 mg/kg/day, high dose: 40 mg/kg/day) in rodents. After a 21-day experimental period, a significant decline in both superoxide dismutase and catalase was observed in both stressed and stress hormone-treated animals. The brain levels of glutathione as well as the activities of glutathione-S-transferase and glutathione reductase were also significantly decreased, while lipid peroxidation levels were significantly increased in comparison to controls. A direct pro-oxidant effect of stress hormones in the brain during physical and psychological stress was observed, indicating important implications for oxidative stress as a major pathological mechanism during chronic stress and a consequent target option for anti-stress therapeutic interventions.

Long term dietary restriction ameliorates swimming exercise-induced oxidative stress in brain and lung of middle-aged rat.

Exhaustive exercise may generate oxidative stress in brain and reported findings are conflicting. Long term dietary restriction (DR) may be useful in the inhibiting of free oxygen radicals generated during exhaustive exercise in the brain of rat. Hence, in this study we evaluated beneficial effects of long term DR on the oxidative stress and antioxidant enzyme systems in brain cortex and lung in rats after different intensities of swimming exercise. Sprague-Dawley rats (60) were assigned as DR and ad libitum (AL) groups, and each group was further subdivided into three groups namely control (sedentery), submaximal exercise (endurance exercise) and maximal exercise (exhaustive swimming exercise) groups. Animals in the endurance exercise group swam 5 days/week for 8 weeks while exhaustive swimming group was subjected to an acute bout of exercise. With the increase in intensity of exercise, degree of lipid peroxidation (LP) and protein oxidation (PO) were also increased in DR and AL groups; however rate of increase was lower in DR group than AL group. Glutathione (GSH) and glutathione peroxidase (GSH-Px) activity were lower but glutathione reductase (GR) activity was higher in DR group compared to AL group in endurance and exhaustive swimming exercise. With increase in exercise intensity, GSH and GR enzyme activity decreased, whereas an increase was observed in GSH-Px enzyme activity. There was no difference in LP, PO, GSH and GR activity between DR and AL groups. GSH-Px activity in brain cortex was significantly lower in DR group than in AL group and sedentary rats. Results indicate that long term dietary restriction may protect against endurance and exhaustive swimming exercise-induced oxidative stress in rats by inhibiting oxidative stress.

The Relationship between Leaf Rolling and Ascorbate-Glutathione Cycle Enzymes in Apoplastic and Symplastic Areas of Ctenanthe setosa Subjected to Drought Stress

The ascorbate-glutathione (ASC-GSH) cycle has an important role in defensive processes against oxidative damage generated by drought stress. In this study, the changes that take place in apoplastic and symplastic ASC-GSH cycle enzymes of the leaf and petiole were investigated under drought stress causing leaf rolling in Ctenanthe setosa (Rose.) Eichler (Marantaceae). Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate forms). Glutathione reductase (GR), a key enzyme in the GSH regeneration cycle, and ascorbate (ASC) were present in apoplastic spaces of the leaf and petiole, whereas dehydroascorbate reductase (DHAR), which uses glutathione as reductant, monodehydroascorbate reductase (MDHAR), which uses NAD(P)H as reductant, and glutathione were absent. GR, DHAR and MDHAR activities increased in the symplastic and apoplastic areas of the leaf. Apoplastic and symplastic ASC and dehydroascorbate (DHA), the oxidized form of ascorbate, rose at all scores except score 4 of symplastic ASC in the leaf. On the other hand, while reduced glutathione (GSH) content was enhanced, oxidized glutathione (GSSG) content decreased in the leaf during rolling. As for the petiole, GR activity increased in the apoplastic area but decreased in the symplastic area. DHAR and MDHAR activities increased throughout all scores, but decreased to the score 1 level at score 4. The ASC content of the apoplast increased during leaf rolling. Conversely, symplastic ASC content increased at score 2, however decreased at the later scores. While the apoplastic DHA content declined, symplastic DHA rose at score 2, but later was down to the level of score 1. While GSH content enhanced during leaf rolling, GSSG content did not change except at score 2. As well, there were good correlations between leaf rolling and ASC-GSH cycle enzyme activities ...

Antioxidative response of Lemna polyrrhiza L. to cadmium stress.

Growth, lipid peroxidation, different antioxidative enzymes and metal accumulation were studied in Lemna polyrrhiza treated with different concentrations (1-40 ppm) of CdSO4. The growth of the plant was slightly enhanced with 1 ppm, while higher concentrations retarted growth and multiplication of fronds, the effect being concentration and dose dependant. Increase in malondialdehyde content was insignificant after the first week but a prolonged exposure led to significant (p < 0.05) increase of about 38% and 45% over the control in 20 and 30 ppm, respectively after four weeks. Catalase (EC 1.11.1.6; CAT) activity increased at low concentration, but it declined to 42% and 54% at 40 ppm after 6 and 30 days, respectively Superoxide dismutase (EC 1.15.1.1; SOD), ascorbate peroxidase (EC 1.11.1.11;APx) and glutathione reductase (EC 1.6.4.2) increased at both low as well at high concentrations, but a prolonged exposure to high concentration of Cd (40 ppm) led to significant (p < 0.05) decline in the mean activities of these antioxidant enzymes. Accumulation of Cd in biomass was concentration and time dependant However at high concentration of 40 ppm, Cd accumulation did not increase significantly (p < 0.05) with time. Increased activities of antioxidant enzymes in Cd treated plants suggest that metal tolerance in L. polyrrhiza might be associated to the changes of antioxidant enzymatic activities.

Metabolismo del glutatión y desarrollo posnatal del pulmón de la rata / Glutathione metabolism during postnatal development of the rat lung

Background: Significant changes in lung antioxidants occur in preparation for birth. Little is known about physiological regulation of antioxidants in the postnatal period. Aim: To study the glutathione system in the lungs during postnatal development. Material and methods: In the lungs of 7, 15, 21, 50 and 70 days old Sprague-Dawley rats we measured total and oxidized glutathione content as well as the activity of the limiting enzyme in glutathione synthesis (y-GCS) and of the enzymes glutathione peroxidase (GPx) and glutathione reducíase (GRd). Results: Between 7 and 15 days the activities of GPx and GRd increase 32 percent and 26 percent, respectively (p <0.001). Whereas GPx activity remains high throughout the rest of the study period, GRd activity decreases progressively reaching adulthood values at 7 days. y-GCS activity shows a gradual increase that reaches significance at 50 days when it doubles values observed at 7 days (p <0.05). A significant correlation was found between GPx and GRd activities over the entire period (r =0.62, p <0.0001). Strength of the correlation is age dependent due to the differences in time course of the enzyme changes. Whereas total GSH does not change, oxidized glutathione decreases from 7 percent at 7 and 15 days to 4 percent later on (p <0.01). Conclusions: The activity of several enzymes involved in glutathione metabolism increases during postnatal development of the rat lung. Interpretation of lung responses to injurious agents needs to be done taking into consideration the physiological regulation of antioxidants during postnatal development.

Effect of T3 treatment on glutathione redox pool and its metabolizing enzymes in mitochondrial and post-mitochondrial fractions of adult rat testes.

T3 (3,3', 5-triiodo-L-thyronine; 20 microg/100 g body weight/day in 0.01 N NaOH, i.p for 1, 3 and 5 days) treatment modulated reduced (GSH) and oxidized (GSSG) glutathione contents along with the activities of its metabolizing enzymes (such as glutathione peroxidase, glutathione reductase and glutathione S-transferase) in the testis of Wistar rats. However, the magnitude and nature of changes in the above biochemical parameters in response to T3 treatment were noticed to be different between mitochondrial and post-mitochondrial fractions. This was accompanied with elevated levels of lipid hydroperoxide and ascorbic acid in the crude homogenate of testis. The level of hydrogen peroxide in the post-mitochondrial fractions of testes did not change on first day, decreased on 3rd day and increased on 5th day of the hormone treatment when compared to respective controls. Nevertheless, its content in mitochondria was significantly elevated in response to all the three durations of the hormone treatment having the highest induction on 3rd day. The changes observed in the levels of GSH and GSSG and its metabolizing enzymes in response to T3 treatment reflect an alteration in the redox state of testis, which may be a causative factor for the impairment of testicular physiology as a consequence of oxidative stress.

UV-B induced changes in antioxidant enzymes and their isoforms in cucumber (Cucumis sativus L.) cotyledons.

To assess the role of antioxidant defense system on exposure to ultra-violet-B (UV-B) radiation, the activities of antioxidant enzymes superoxide dismutase (SOD), ascorbic acid peroxidase (APX), glutathione reductase (GR) and guaiacol peroxidase (GPX), as well as the level of antioxidants ascorbic acid (AA) and alpha-tocopherol were monitored in cucumber (Cucumis sativus L. var long green) cotyledons. UV-B enhanced the activity of antioxidant enzymes as well as AA content, but decreased the level of alpha-tocopherol. Significant increase was observed in the activities of SOD and GPX. Analysis of isoforms of antioxidant enzymes by native-PAGE and activity staining revealed three isoforms of GPX in unexposed dark-grown cotyledons (control), and their intensity was enhanced by UV-B exposure. In addition, four new isoforms of GPX were observed in cotyledons after UV-B exposure. Although no new isoforms were observed for the other antioxidant enzymes, the activities of their existing isoforms were enhanced by UV-B.

Post natal antioxidant enzyme activity of rat brain regions during developmental lead exposure.

This study reports the effects of low level developmental Pb exposure on specific brain regions like hippocampus, cerebellum and cerebral hemispheres of antioxidant enzyme activities. Wistar dams were exposed to 50 ppm, 100 ppm and 500 ppm of Pb acetate in drinking water during pregnancy and lactation (gestation day 6 through PND 21 (post natal day) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were determined in the hippocampus, cerebellum and cerebral hemispheres of pups during treatment period (PND 7, 14, and 21 days) and also during withdrawl period (PND 35, 45, 60 and 90 days). During treatment period, SOD activity significantly (p < 0.05) decreased in all regions of all the treated groups with maximum decrease in 500 ppm treated group of 21 days, while GSH-Px and GR activities increased with maximum increase in 21 days aged 500 ppm group. During withdrawl period, the activities of all enzymes were significantly (p < 0.05) reversed. Thus the perinatal exposure of dams to variable dosages of low level lead results in characteristic neurochemical alterations in rat brain regions due to impaired antioxidants function.

Actividad de la glutatión reductasa en el embarazo diabético / Glutathione reductase activity in diabetic pregnancy

ANTECEDENTES: El predominio de la diabetes gestacional está aumentando en nuestra población y sus efectos en el metabolismo celular y estatus oxidativo están siendo estudiados. OBJETIVO: Determinar si existe una relación entre la actividad de la glutatión reductasa eritrocitaria, evaluada a través del test CAGRE y la diabetes gestacional. MÉTODO: Estudio transversal de casos y controles, incluyó a 30 embarazadas con diagnóstico de diabetes gestacional y 30 sin patologías asociadas, pertenecientes a la Maternidad del Hospital Barros Luco-Trudeau, Santiago de Chile. La actividad de la glutatión reductasa de eritrocitos fue determinada espectrofotométricamente a través del test CAGRE, la que fue relacionada con variables maternas como: edad, hematocrito, presencia de antecedentes de enfermedades familiares, estado nutricional materno e índice de masa corporal. Para comparar las variables entre ambos grupos, se realizaron medidas de disparidad, posición y análisis de la correlación. RESULTADOS: El grupo de madres diabéticas presentó edad materna, índice de masa de corporal y antecedentes de diabetes gestacional mayores que el grupo control, aunque sin diferencia estadísticamente significativa. El predominio de anemia y la respuesta al suplemento del cofactor FAD en la actividad de la glutatión reductasa eritrocitaria fue similar entre los grupos. La mayor incidencia de diabetes familiar en el grupo control fue estadísticamente significativa. La distribución de los valores de CAGRE, utilizado también como un indicador de los niveles de riboflavina, mostró en el grupo de casos riesgo medio a alto de malnutrición, mientras que en el grupo control la tendencia fue normal o de riesgo bajo. CONCLUSIÓN: Las embarazadas diabéticas gestacionales, presentaron mal nutrición y un estrés oxidativo mayor que el grupo control, evidenciado por el test de CAGRE.

BACKGROUND: The prevalence of the gestational diabetes is increasing in our population and its effects in the cellular metabolism and oxidative status had been studied. OBJECTIVE: Determine if exists a relationship between the erythrocyte glutathione reductase activity evaluated by EGRAC test and the gestational diabetes. METHODS: This traversal study of cases and controls, included at 30 pregnant with diagnostic of gestational diabetes and 30 without associate pathologies, belonging to the Maternity of the Hospital Barros Luco-Trudeau, Santiago-Chile. The activity of the glutathione reductase was determined by spectrophotometric assay through the EGRAC test, and their values were related with maternal variables as: age, hematocrite, presence of antecedents of family illnesses, maternal nutritional status and the body mass index. To compare the variables between both groups, they were carried out measures of disparity, position and analysis of the correlation. RESULTS: We determine that the group of diabetic mothers was older, with higher body mass index and a bigger frequency of antecedents of gestational diabetes that the control group, although without significant difference. The prevalence of anemia and the answer to the supplement with FAD in the activity of the glutathione reductase was similar among the groups. On the other hand, the incidence of familiar diabetes in the group control was bigger. The distribution of the values of EGRAC, also used as an indicator of the riboflavin levels, showed in the group of cases half risk to high of malnutrition, while in the group control the tendency was normal or low risk. CONCLUSION: We can conclude that the gestational diabetics pregnant presented malnutrition and higher oxidative stress that the control group, evidenced by means of the EGRAC test.

Cytogenetic effects of a mixture of selected metals following subchronic exposure through drinking water in male rats.

The current study examines the genotoxic effects of subchronic exposure via drinking water to a mixture of eight metals (arsenic, cadmium, lead, mercury, chromium, nickel, manganese and iron) found as contaminants of water sources in different parts of India and its possible association with oxidative stress. Male rats were exposed to the mixture at 0, 1, 10 and 100 times the mode concentration of each metal daily for 90 days. Another dose group at concentration equivalent to maximum permissible limit (MPL) for each metal and a reference group given ip cyclophosphamide were incorporated. The mixture at 100x level significantly increased chromosomal aberrations and micronuclei induction (2.4 folds) in bone marrow cells and reduced the ratio of polychromatic to normochromatic erythrocytes by 25%. The mixture significantly increased sister chromatid exchange in bone marrow (1.67 and 2.3 folds) and spleen (1.57 and 1.98 folds) cells with both 10x and 100x doses. Cyclophosphamide was more potent than the mixture in causing cytogenetic damage in these parameters. In rat spleen, the mixture at 10x and 100x doses caused dose-dependent increase in lipid peroxidation (25.95 and 52.71%) and decrease in the activities of superoxide dismutase (20.36 and 40.62%), catalase (18.24 and 35.50%), glutathione peroxidase (22.33 and 36.12%) and glutathione reductase (19.22 and 31.35%) and in the level of GSH (19.76 and 35.15%). The results suggest that the mixture induced genotoxicity in rat bone marrow and spleen cells at concentrations relatively higher than that found in groundwater sources and the genotoxic effect could relate to induction of oxidative stress. However, observations with lower doses indicate that additive or synergistic interactions following exposure to metal components at MPL levels or at mode concentrations of contemporary groundwater levels in India may not result in clastogenicity in male rats.

Glutathione and associated enzymes in toxic cataractogenesis-selenite model.

Glutathione, gamma-glutamyl cysteine synthetase (gamma -GCS) and glutathione reductase (GSH-R) activity were determined biochemically in the lens during various stages after subcutaneous administration of sodium selenite in multiple low dosages and single high dosages. The GSH concentration and gamma-GCS and GSH-R activity declined progressively after the selenite administration. The changes observed were discussed in relation to the possible role of selenite interaction with GSH and the enzymes.