首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 437 毫秒
1.
In two separate experiments rats fed vitamin E-deficient, normal or high vitamin E-supplemented diets were intermittently exposed to 15 ppm ± 1.0 ppm nitrogen dioxide (NO2) over a 5-week (4 days/week, total of 31.5 h exposure) or an 18-week (5 days/week, total of 93.5 h exposure) period. In the 5-week, NO2-exposed rats, the blood methemoglobin levels were not influenced by NO2 exposure or the level of vitamin E in the diet. Tissues of the rats exposed to NO2 for 18 weeks showed some histological changes; in the lung, increased atelectasis and alveolar thickening and in the liver, increased granular changes, karyolysis and karyorhexis. These differences were suppressed by increasing levels of dietary vitamin E. Tissue lipofuscin pigment (LFP) concentrations were not affected by NO2 exposure or dietary vitamin E. Fatty acid distribution of lung lipid extracts showed no changes due to NO2 exposure; however, some effects of dietary vitamin E could be seen. The results suggest that intermittent NO2 exposure, under the described conditions, did not cause ultimate changes of the biochemical parameters measured.  相似文献   

2.
We examined the influence of dietary selenium (Se) on the pulmonary biochemical response to ozone (O3) exposure. For 11 weeks, weanling female strain A/St mice were fed a test diet containing Se either at 0 ppm (-Se) or 1 ppm (+Se). Each diet contained 55 ppm vitamin E (vit E). Mice from each dietary group were exposed to 0.8 +/- 0.05 ppm (1568 +/- 98 micrograms/m3) O3 continuously for 5 days. After O3 exposure, they were killed along with a matched number of unexposed controls, and their lungs were analyzed for various biochemical parameters. The Se contents of lung tissue and whole blood were determined, and the levels were seven- to eightfold higher in +Se mice than in -Se mice, reflecting the Se intake of the animals. In unexposed control mice, Se deficiency caused a decline in glutathione peroxidase (GP) activity relative to +Se group. After O3 exposure, the GP activity in the -Se group was associated with a lack of stimulation of glutathione reductase (GR) activity and the pentose phosphate cycle (PPC) as assessed by measuring glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activities. In contrast, the +Se group after O3 exposure exhibited increases in all four enzyme activities. Other parameters, e.g., lung weight, total lung protein, DNA and nonprotein sulfhydryl contents, and O2 consumption, were not affected by dietary Se in the presence or absence of O3 exposure. The data indicate that dietary Se alters the GP activity, which in turn influences the GR and PPC activities in the lung evidently through a reduced demand for NADPH. The level of vit E in the lung was found to be twofold higher in the -Se group than in the +Se group, suggesting a compensatory relationship between Se and vit E in the lung. With O3 exposure, both Se and vit E contents further increased in the lungs of each dietary group. It is plausible that Se and vit E under oxidant stress are "mobilized" to the lung from other body sites.  相似文献   

3.
《Inhalation toxicology》2013,25(5):515-520
Abstract

To clarify the relationship between exposure to nitrogen dioxide (NO2) and mast-cell responses, rats and guinea pigs were exposed to 0, 1.0, 2.0, and 4.0 ppm NO2 for 12 wk. Although lung wet weights were not changed in both rats and guinea pigs, the number of lung cells from 2.0 and 4.0 ppm NO2-exposed rats were significantly decreased compared to that of control. No difference was observed in the number of lung mast cells from rats and guinea pigs exposed to NO2. in lung mast cells from rats, immunoglobulin E (IgE) mediated histamine release was slightly decreased, but A23187-induced histamine release was not changed. On the contrary, in lung mast cells from guinea pigs, IgE-mediated histamine release was increased in a dose-dependent fashion, though no changes in A23187-induced histamine release were observed. These results suggest that different sensitivity for NO2 exposure exists in lung mast cells from rats and guinea pigs.  相似文献   

4.
To delineate the effect of dietary supplementation with vitamin E (Vit E) alone or in combination with riboflavin (Rib) or selenium (Se) or both, on biological oxidative damage in rat brain and lungs we exposed rats to hyperbaric oxygen (HBO) and measured the activities of glutathione reductase (GSSG-R), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glucose-6-phosphate dehydrogenase (G-6-PD) prior to or 48 h after exposure. Rats fed the dietary supplements, and a control group maintained on an unsupplemented diet, for 30 d, were each divided into 2 subgroups, of which 1 was exposed to 4.5 absolute atmospheres (ATA) of 100% oxygen for 30 min, hereafter referred to as "exposed". The remaining subgroups were left unexposed. Pre-exposure GSSG-R activity in brain was elevated in all experimentally fed groups (ranging from 23 to 84%) compared with the unexposed control, whereas GSH-Px, G-6-PD and SOD activities were unchanged. The lungs showed significant increases in pre-exposure GSSG-R, ranging from 15 to 28%, and GSH-Px, ranging from 13 to 23%, activities in all the groups fed the supplemental nutrients, except those on Vit E alone. Increases in G-6-PD activity were observed only in those fed supplements of Rib. In most cases exposure to oxygen caused an increase in GSSG-R, GSH-Px and G-6-PD activities. However the increases were higher in the supplemented groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Abstract: We attempted to modify the resistance of rats to hyperbaric oxygen (HBO)-induced central nervous system (CNS) toxicity, by increasing the tissue antioxidant potential through dietary factors. Groups of rats were fed excesses of vitamin E (VIT E) alone or in combinations with riboflavin (RIB), selenium (Se) or both, for 30 days. A control group was maintained on an unsupplemented diet. On the 23rd day animals to be exposed were implanted with chronic electrodes for electrocorticographic (ECoG) recording. Later, each group was divided into two subgroups, of which one was exposed to 4.5 atmospheres absolute (ATA) of 100% oxygen (O2) for 30 min., hereafter referred to as “exposed”, noting the time of appearance of first electrical discharge (FED) in their ECoG. The remaining subgroups were left unexposed. Forty-eight hours later, all animals were sacrificed and some of their tissues were analyzed for glutathione (GSH). The GSH level in the liver, brain, lungs and blood of all experimental subgroups were significantly higher than in the control unexposed counterparts. Combinations of RIB and/or Se with VIT E failed to show a greater increase in GSH over VIT E alone. This increase was, however, not accompanied by a meaningful delay in the appearance of FED. Forty-eight hours post-exposure, the brain GSH levels of all exposed subgroups were still lower than the respective pre-exposure levels. Yet, in the treated exposed subgroups the GSH levels observed 48hr after exposure were already higher than in the untreated unexposed controls. Thus, the dietary factors studied may enhance the reparative potential of oxidative tissue injury, but do not afford increased resistance of the brain to HBO, as judged by the respective FED times.  相似文献   

6.
Metal working fluids (MWFs) have been widely known to cause asthma and neoplasia of the larynx, pancreas, rectum, skin and urinary bladder (Textbook of Clinical Occupational and Environmental Medicine (1994) 814; Am. J. Ind. Med. 32 (1997) 240; Am. J. Ind. Med. 33 (1997) 282; Am. J. Ind. Med. 22 (1994) 185). Other non-neoplastic respiratory effects in industrial workers attributed to MWFs include increased rates of cough, phlegm production, wheeze, chronic bronchitis and chest tightness (Eur. J. Resir. Dis. 63(118) (1982), 79; J. Occup. Med. 24 (1982) 473; Am. J. Ind. Med. 32 (1997) 450). The epidemic and endemic nature of immune mediated lung morbidity commonly known as hypersensitivity pneumonitis in workers from several different industries using MWFs has been well documented (J. Allergy clin. Immunol. 91 (1993) 311; Chest 108 (1995) 636; MMWR45 (1996) 606; Am. J. Ind. Med. 32 (1997) 423). We studied morphological/functional and antioxidant outcomes in lungs after inhalation exposure of vitamin E deficient mice to MWF (27 mg m(-3) 17 weeks, 5 days a week, 6 h a day). Mice were given vitamin E deficient (<10 IU kg(-1) vitamin E) or basal diets (50 IU kg(-1) vitamin E) for 35 weeks. Inhalation exposure to MWF started after 18 weeks on diet. Microscopic observation of lungs from mice given vitamin E deficient or sufficient diets revealed no inflammation or morphological alteration after exposure to MWF. Mice given vitamin E deficient diet exhibited a significant decrease (P<0.05) in breathing rate, peak inspiratory/expiratory flow, minute ventilation, and tidal volume compared with sufficient controls. However, no differences were found after exposure to MWF in pulmonary function, with the exception of tidal volume which also significantly decreased (P<0.05). Exposure to MWF reduced vitamin E, protein thiol and ascorbate level in lungs. Exposure to MWF in combination with a vitamin E deficient diet resulted in significantly enhanced accumulation of peroxidative products compared with vitamin E deficient controls. This is the first report that describes the increase of oxidative stress in the lungs after MWF exposure.  相似文献   

7.
Pentane production by rats fed a stock diet exhibited a dose-dependent relationship with carbon tetrachloride (CCl4) administered intraperitoneally. Total pentane produced during a 2-h test period following administration of a single dose of 30 μl CCl4/100 g body wt. was greater by rats fed a vitamin Edeficient diet than by rats fed a diet supplemented with vitamin E. Vitamin Esupplemented rats pretreated with 30 μl CCl4 daily for 4 days produced less pentane following administration of 60 μl CCl4 on day 5 than did rats not pretreated with CCl4; conversely, rats fed a vitamin E-deficient diet and similarly treated produced more pentane than did non-pretreated rats. This study confirmed that CCl4 toxicity involves lipid peroxidation and that protection is provided by vitamin E. The usefulness in toxicological studies of monitoring pentane as an index of lipid peroxidation in vivo was shown.  相似文献   

8.
This study reports the effect of the fat-soluble vitamin A or vitamin E and grape seed proanthocyanidin extract (GSPE) on oxidative DNA damage estimated by 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) contents in urine and leukocyte of rats. Little is known about the antioxidant potency of dietary anthocyanidins and consequently, the aim of this study was to establish whether anthocyanidins could act as putative antioxidant micronutrients. Seven groups of male Sprague-Dawley rats were fed during 47 days with the following diets: a basic diet, two deficient vitamin A or E diets, two supplemented vitamin A or E diets and two supplemented diets enriched with two doses of grape seed proanthocyanidin extract. At the end of the diet intervention period, 24h, urine and blood were collected. The levels of 8-oxodG in leukocytes rats were significantly lower in the supplemented vitamin A, E and GSPE diet groups with respect to the control group. However, consumption of alpha-tocopherol, vitamin A or GSPE had no effect on the excretion of the oxidised nucleoside 8-oxodG. These results suggest that a vitamin E and A and GSPE enriched-diets have a protective effect on oxidative DNA damage limited to rat leukocytes.  相似文献   

9.
1. Thoracic aortae, isolated from rats supplemented with dietary vitamin E after vitamin E deficiency, were analysed for changes in vascular reactivity. 2. Following 4 or 12 months of dietary vitamin E deficiency, endothelium-dependent vasodilator responses to acetylcholine were significantly impaired. However, when animals were fed after the first 4 months of vitamin E deprivation with a vitamin E-supplemented diet for 8 months, endothelium-mediated responses were completely restored. 3. In contrast, the endothelium-independent vasodilator or vasoconstrictor responses to sodium nitroprusside and noradrenaline, respectively were not altered either by vitamin E deficiency or supplementation. 4. These data indicate that vitamin E supplementation reversed the impairment of endothelial cell function which occurs during vitamin E deficiency.  相似文献   

10.
The effect of dietary vitamin E on cellular responses to nitrite was studied in rats. One-month-old male Sprague-Dawley rats were fed a basal vitamin E-deficient diet with or without 100 ppm vitamin E and 1000 ppm sodium nitrite (NaNO2) for 9 weeks. In addition to a high mortality rate, nitrite-fed rats maintained on a vitamin E-deficient diet exhibited a marked increase in liver necrosis, tubular nephrosis and myodegeneration, as well as greater biochemical and hematological alterations when compared to the control animals. No animal mortality or histopathologic lesions in any tissues were observed in rats receiving a vitamin E-supplemented diet with or without nitrite. The results suggest that depletion of vitamin E renders rats more susceptible to the adverse effect of nitrite, and that nitrite administration potentiates deficiency of vitamin E in rats.  相似文献   

11.
Vitamin B6 is a cofactor for more than 140 essential enzymes and plays an important role in maternal health and fetal development. The goal of this study was to investigate the effects of maternal vitamin B6 on DNA damage and oxidative stress status in rat dams and their offspring. Female Wistar rats were randomly assigned to three dietary groups fed a standard diet (control diet), a diet supplemented with 30 mg/kg of vitamin B6, or a deficient diet (0 mg/kg of vitamin B6) for 10 weeks before and during mating, pregnancy and lactation. The dams were euthanized at weaning, and their male pups were euthanized either 10 days or 100 days after birth. We found that maternal vitamin B6 deficiency increased the micronucleus frequency in peripheral blood and bone marrow cells and also increased the concentration of hepatic TBARS (thiobarbituric acid reactive substances) in newborn pups (10 days old). In conclusion, maternal 5- to 6-fold over-supplementation of vitamin B6 had no adverse effects, however its deficiency may induce chromosomal damage and hepatic lipid peroxidation in the offspring.  相似文献   

12.
The ability of trialkyllead compounds to induce lipid peroxidation (measured by ethane production in vivo) was tested in rats fed a diet deficient in vitamin E and selenium or supplemented with 200 IU of dl-α-tocopherol or 0.6 ppm selenium supplied as sodium selenite. Trimethyllead induced lipid peroxidation in vivo to the greatest extent in vitamin E and selenium-deficient animals. Vitamin E and, to a lesser extent selenium, offered protection against this effect of trimethyllead. In the case of triethyllead, metabolism of the chemical caused the release of large amounts of ethane and ethylene, thereby preventing the use of ethane production as an index of lipid peroxidation. Such decomposition of triethyllead was lower in vitamin E and selenium-deficient animals compared to supplemented animals, and selenium in the diet promoted increased release of ethane and ethylene from triethyllead.  相似文献   

13.
The effect of acute nitrogen dioxide (NO2) exposure on prostacyclin synthesis in the rat lung was studied. Male Wistar rats were exposed to 5, 10, 15, 20 and 25 ppm NO2 for 24 h. Dose-dependent decrease in prostacyclin-synthesizing activities of both homogenized and intact lung was observed. This decrease in prostacyclin synthesis following NO2 exposure may be related to formation of lipid peroxides due to NO2 exposure and to damage of pulmonary epithelial cells and endothelial cells by NO2 exposure.  相似文献   

14.
Free radical generation is an important step in the pathogenesis of ethanol-associated liver injury. Administration of ethanol induces an increase in lipid peroxidation both by enhancing the production of oxygen reactive species and by decreasing the levels of endogenous antioxidants. This work focuses on the generation of free radicals provoked by an acute ethanol dose in rats, and the role of different dietary levels of vitamin E. The objective of this investigation was to study the effect of three different dietary levels of vitamin E (deficient, control and supplemented with 20 times higher levels) on plasma and liver lipid peroxidation (assayed by TBARS), vitamin E in plasma and liver, and hepatic glutathione concentration, in rats receiving the different diets. The animals were submitted to an acute dose of ethanol (5 g/kg body weight) administered by gavage at the end of an experimental 4 week period and were sacrificed at 0, 2, 4, 8 and 24 h after ethanol administration. Dietary vitamin E caused a dose-dependent increase in liver and plasma concentration of the vitamin, but ethanol administration decreased hepatic vitamin E in all groups. TBARS concentrations were higher in liver of rats that received the deficient diet, independent of ethanol, however, liver TBARS concentrations were low in control and supplemented groups, but increased with ethanol ingestion. Glutathione levels were lowered by ethanol administration in all groups, in different times, but recovered to this original level in 24 h time. In conclusion, vitamin E deficiency alone induces liver lipid peroxidation in rats, acute administration of ethanol affect vitamin E and GSH level and maintenance of adequate or higher vitamin E levels acts as a protective factor against free radical generation.  相似文献   

15.
Swiss Webster mice were exposed to either 4.8 ppm (9024 μg/m3) nitrogen dioxide (NO2), 0.45 ppm (882 μg/m3) ozone (O3), or their combination intermittently (8 hr daily) for 7 days, and the effects were studied in the lung by a series of physical and biochemical parameters, including lung weight, DNA and protein contents, oxygen consumption, sulfhydryl metabolism, and activities of NADPH generating enzymes. The results show that exposure to NO2 caused relatively smaller changes than O3, and that the effect of each gas alone under the conditions of exposure was not significant for most of the parameters tested. However, when the two gases were combined, the exposure caused changes that were greater and significant. Statistical analysis of the data shows that the effects of combined exposure were more than additive, i.e., they might be synergistic. The observations suggest that intermittent exposure to NO2 or O3 alone at the concentration used may not cause significant alterations in lung metabolism, but when the two gases are combined the alterations may become significant.  相似文献   

16.
In order to examine the effects of NO2 on the fatty acid content of the lung and liver phospholipids, the phospholipid fractions of rats exposed to 20 ppm NO2 for 20 and 40 h were extracted and analyzed using gas chromatography. Among the fatty acid species in the lung, the relative amount of palmitic acid, palmitoleic acid and linoleic acid increased significantly, whereas myristic acid, stearic acid and oleic acid decreased significantly after exposure to NO2. These changes in the composition of fatty acids are discussed in comparison with the results of acute, subacute and chronic exposure to NO2 reported by other workers. In the case of the fatty acid species in the liver, a significant increase for stearic acid and arachidonic acid and a decrease in oleic acid were observed.  相似文献   

17.
We have previously found that ascorbic acid (AA) deficiency in guinea pigs enhances the pulmonary toxicity of nitrogen dioxide (NO2). The present study showed that exposure to NO2 (4.8 ppm, 3 hr) significantly increased lung lavage fluid protein (a sensitive indicator of pulmonary edema) only in guinea pigs fed rabbit chow (a diet not supplemented with vitamin C) for at least 7 days, at which time lung AA was about 50% of normal. The rabbit chow diet did not cause reduced body weight as did commercial synthetic scorbutic diets, even when they were supplemented with AA. After 14 days of feeding rabbit chow, lung AA was reduced to 15% of control. At this time, alpha-tocopherol (AT) in the same lungs was reduced to 85% of control, and lung nonprotein sulfhydryls (NPSH) were increased to 114% of control. Exposure of the guinea pigs to NO2 (4.5 ppm, 16 hr) increased wet lung weight and further altered the antioxidants in deficient (but not normally fed) animals in the following manner: NPSH content was increased to 130% of control, AT was decreased to 74% of control, and AA was increased from 15 to 50% of control. These findings suggest that depletion of AA in guinea pigs removes an important defense against NO2. The lung appears to be able to partially compensate for the dietary lack of antioxidant by accumulating AA from other tissues and by increasing NPSH concentrations. However, sufficient exposure to NO2 leads to oxidation of AT and pulmonary edema. Conditions in which NO2 produced edema were accompanied by only a slight consumption of AT, and no detectable oxidation of lung AA or NPSH.  相似文献   

18.
Various drugs have been shown to stimulate surfactant phospholipid metabolism. Particularly β-adrenergic agonists play an important role under physiologic conditions. For the first time we have studied whether nitrogen dioxide (NO2) inhalation alters β-adrenergic regulation of surfactant phospholipid metabolism in the model of the isolated lung. Rats were continuously exposed in vivo to a 5 ppm NO2-containing atmosphere for 48 hr. The lungs were isolated and perfused in presence of the β-adrenergic agonist dopexamine and surfactant metabolism was studied in three lung compartments: (1) lung lavage, (2) lung tissue, and (3) lavagable free alveolar cells. We found that (1) in normal rat lungs dopexamine increased the incorporation of palmitate and choline from the perfusate into lung lavage phospholipids. In nitrogen dioxide exposed rat lungs β-adrenergic stimulation did not cause an increase in precursor incorporation. No significant difference in unstimulated precursor incorporation was found for normal and NO2-exposed rat lungs. (2) Lung tissue from rats exposed to NO2 showed a decreased precursor incorporation into disaturated phosphatidylcholine due to an augmented cellular pool size. (3) Lavagable alveolar cells showed an increased palmitate uptake after nitrogen dioxide inhalation and by β-adrenergic stimulation. From these data we conclude that nitrogen dioxide inhalation impairs the β-adrenergic regulation of surfactant phospholipid metabolism. Moreover these data underline the importance of β-adrenergic agonists in surfactant metabolism.  相似文献   

19.
Vitamin D3 deficiency has been correlated with altered expression of genes associated with increased blood pressure (BP); however, the role of vitamin D3 supplementation in the genetic mechanisms underlying hypertension remains unclear. Thus, the aim of this study was investigate the consequences of vitamin D3 supplemented (10,000 IU/kg) or deficient (0 IU/kg) diets on regulation of expression of genes related to hypertension pathways in heart cells of spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) controls. An additional aim was to assess the impact of vitamin D3 on DNA damage and oxidative stress markers. The gene expression profiles were determined by PCR array, DNA damage was assessed by an alkaline comet assay, and oxidative stress markers by measurement of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels. In SHR rats data showed that the groups of genes most differentially affected by supplemented and deficient diets were involved in BP regulation and renin-angiotensin system. In normotensive WKY controls, the profile of gene expression was similar between the two diets. SHR rats were more sensitive to changes in gene expression induced by dietary vitamin D3 than normotensive WKY animals. In addition to gene expression profile, vitamin D3 supplemented diet did not markedly affect DNA or levels of TBARS and GSH levels in both experimental groups. Vitamin D3 deficient diet produced lipid peroxidation in SHR rats. The results of this study contribute to a better understanding of the role of vitamin D3 in the genetic mechanisms underlying hypertension.

Abbreviations: AIN, American Institute of Nutrition; EDTA, disodium ethylenediaminetetraacetic acid; GSH, glutathione; PBS, phosphate buffer solution; SHR, spontaneously hypertensive rats; TBARS, thiobarbituric acid reactive substances; WKY, Wistar Kyoto.  相似文献   


20.
The present study aimed to investigate the effect of the new tyrosine kinase inhibitor, nilotinib on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats and explore its possible mechanisms. Male Sprague-Dawley rats were given nilotinib (10 mg/kg) by oral gavage twice daily for 1 week prior to exposure to aerosolized LPS. At 24 h after LPS exposure, bronchoalveolar lavage fluid (BALF) samples and lung tissue were collected. The lung wet/dry weight (W/D) ratio, protein level and the number of inflammatory cells in the BALF were determined. Optical microscopy was performed to examine the pathological changes in lungs. Malondialdehyde (MDA) content, superoxidase dismutase (SOD) and reduced glutathione (GSH) activities as well as nitrite/nitrate (NO2/NO3) levels were measured in lung tissues. The expression of inflammatory cytokines, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and inducible nitric oxide synthase (iNOS) were determined in lung tissues. Treatment with nilotinib prior to LPS exposure significantly attenuated the LPS-induced pulmonary edema, as it significantly decreased lung W/D ratio, protein concentration and the accumulation of the inflammatory cells in the BALF. This was supported by the histopathological examination which revealed marked attenuation of LPS-induced ALI in nilotinib treated rats. In addition, nilotinib significantly increased SOD and GSH activities with significant decrease in MDA content in the lung. Nilotinib also reduced LPS mediated overproduction of pulmonary NO2/NO3 levels. Importantly, nilotinib caused down-regulation of the inflammatory cytokines TNF-α, TGF-β1 and iNOS levels in the lung. Taken together, these results demonstrate the protective effects of nilotinib against the LPS-induced ALI. This effect can be attributed to nilotinib ability to counteract the inflammatory cells infiltration and hence ROS generation and regulate cytokine effects.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号