Changes in lipid profiles of liver microsomes of rats following intratracheal administration of DDT or endosulfan

The effect of intratracheal administration of DDT (5 mg/100 g body weight) or endosulfan (1 mg/100 g body weight) to rats for three consecutive days, has been studied on liver lipid metabolism. The administration of DDT but not endosulfan significantly increased the liver weight and the microsomal protein contents. Both DDT and endosulfan treatments significantly increased the contents of microsomal phosphatidylcholine (PC), total-free- and esterified cholesterol. The distribution of unsaturated fatty acids of microsomal PC and PE was increased by DDT treatment. The intratracheal administration of DDT caused fatty infiltration of liver which was probably due to increased synthesis of triglycerides (TG). This is supported by the increased incorporation of radioactive palmitate-1-14C into microsomal TG. However, the increased incorporation of palmitate-1-14C into microsomal PC and phosphatidylethanolamine (PE) after the DDT treatment, was due to the increased transacylation reaction supported by the decreased activity of microsomal phospholipase A. The intratracheal administration of endosulfan did not have pronounced effect on liver fatty infiltration, or transacylation reaction in microsomal PC and PE. However, the results have shown that the treatments of DDT or endosulfan increased the PC contents and the incorporation of radioactive [methyl-3H]choline into PC of microsomes, resulting the increased synthesis of PC via CDPcholine pathway. Thus, the intratracheally administered DDT or endosulfan to rats showed that both the insecticides cause manifestations in the biochemistry of microsomal membrane lipids, although the effects of DDT being more pronounced. Therefore, the translocation effects of these insecticides or metabolites from lung to liver is established.     

Changes in lipid profiles of liver microsomes of rats following intratracheal administration of DDT or endosulfan

Abstract

The effect of intratracheal administration of DDT (5 mg/100 g body weight) or endosulfan (1 mg/100 g body weight) to rats for three consecutive days, has been studied on liver lipid metabolism. The administration of DDT but not endosulfan significantly increased the liver weight and the microsomal protein contents. Both DDT and endosulfan treatments significantly increased the contents of microsomal phosphatidylcholine (PC), total‐free‐ and esterified cholesterol. The distribution of unsaturated fatty acids of microsomal PC and PE was increased by DDT treatment. The intratracheal administration of DDT caused fatty infiltration of liver which was probably due to increased synthesis of triglycerides (TG). This is supported by the increased incorporation of radioactive palmitate‐l‐¹⁴C into microsomal TG. However, the increased incorporation of palmitate‐l‐¹⁴C into microsomal PC and phosphatidylethanolamine (PE) after the DDT treatment, was due to the increased transacylation reaction supported by the decreased activity of microsomal phospholipase A. The intratracheal adminstration of endosulfan did not has pronounced effect on liver fatty infiltration, or transacylation reaction in microsomal PC and PE. However, the results have shown that the treatments of DDT or endosulfan increased the PC contents and the incorporation of radioactive [methyl‐³H]choline into PC of microsomes, resulting the increased synthesis of PC via CDPcholine pathway. Thus, the intratracheally administered DDT or endosulfan to rats showed that both the insecticides cause manifestations in the biochemistry of microsomal membrane lipids, although the effects of DDT being more pronounced. Therefore, the translocation effects of these insecticides or metabolites from lung to liver is established.     

盐酸脱附Pb(Ⅱ)负载氨基膦酸树脂的基本性能

氨基膦酸树脂是一种常用的广谱性重金属螯合树脂,对水中的Pb(Ⅱ)具有很好的选择性分离去除能力,但吸附Pb(Ⅱ)后的树脂再生较为困难。系统研究了盐酸脱附Pb(Ⅱ)-负载氨基膦酸树脂D860的基本性能,优化了基本脱附参数。实验表明,采用盐酸作为脱附剂具有较为良好的脱附效果,10%吸附量树脂脱附反应平衡较快仅需10 min,脱附本身受Pb(Ⅱ)在盐酸溶液中的溶解度影响显著。脱附流速从1 BV/h升高到5 BV/h,脱附效果受到的影响很小。升高温度可以提高PbCl2溶解度,进而提高脱附效率。固定床脱附采用1.0 mol/L盐酸,在1 BV/h和303 K条件下,仅需7 BV脱附剂即可实现较高的脱附效率。     

Characteristics of organic acid profiles in 16 species of wild growing edible mushrooms

The aim of study was to determine 9 organic acids in nine aboveground and seven wood-growing wild edible mushroom species originated from an area under the direct influence of a busy trunk road in Poland. The organic acids in the extracts of samples were identified by reversed-phase column liquid chromatography (RPLC). The presented results show that all the mushroom species were characterized by high variation in the profile and content of the analyzed acids. Each of mushroom species contained oxalic acid, the profiles of the other acids strictly depended on mushroom species. Among aboveground species, the highest total content of organic acids was found in Lepista gilva (267.5 ± 26.6 mg g^?1 dry weight (DW)), while Laccaria amethystina was characterized by the lowest content (37.7 ± 6.5 mg g^?1 DW). Within wood-growing species, the highest content of organic acids was determined in Flammulina velutipes (171.9 ± 26.7 mg g^?1 DW), whereas the lowest content (34.2 ± 2.9 mg g^?1 DW) of the studied acids was observed in Grifola frondosa.     

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 micromol g(-1) fresh weight) than crown-beard (2-4 micromol g(-1) fresh weight) or cutleaf coneflower (0.5-2 micromol g(-1) fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g(-1) fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity.     

Distribution of deoxynivalenol in cerebral spinal fluid following administration to swine and sheep 1

Abstract

Deoxynivalenol (DON) is one of the major mycotoxins produced by Fusarium fungi. In evaluating DON as a potent CNS (emetic, anorexic) agent, its cerebral spinal fluid (CSF) and plasma pharmacokinetics were studied in pigs, a species very sensitive to the effects of DON, and sheep, a more tolerant animal. After intravenous administration, DON was detected very rapidly (<2.5 min) in the CSF of both species, but whereas peak levels (t‐max) occurred at 5–10 min in sheep, in swine it was 30–60 min. It would appear that the very rapid and extensive tissue distribution of DON in swine (Vdγ = 1.13 1 kg^‐1) may be slowing the rate of diffusion of the toxin into the CSF compared to sheep (Vd_β = 0.19 1 kg^‐1) where the toxin is confined essentially to the extracellular compartment. Area under curve calculations indicate approximately 2 1/2 times the amount of toxin eventually reaches the pig CSF compared to sheep CSF.

A good relationship between blood‐CSF DON levels was apparent in both species, although limitations in detection methods made it impossible to resolve a slow terminal phase (γ) in swine CSF which was evident in the plasma profile after iv administration.

Following oral administration of DON to pigs, a close correlation between plasma and CSF DON levels was observed. The toxin could be detected in CSF for up to 20 hr post‐dosing.     

Effects of sodium arsenate exposure on liver fatty acid profiles and oxidative stress in rats

The present study aimed to evaluate the effect of arsenic on liver fatty acids (FA) composition, hepatotoxicity and oxidative status markers in rats. Male rats were randomly devised to six groups (n?=?10 per group) and exposed to sodium arsenate at a dose of 1 and 10 mg/l for 45 and 90 days. Arsenate exposure is associated with significant changes in the FA composition in liver. A significant increase of saturated fatty acids (SFA) in all treated groups (p?<?0.01) and trans unsaturated fatty acids (trans UFA) in rats exposed both for short term for 10 mg/l (p?<?0.05) and long term for 1 and 10 mg/l (p?<?0.001) was observed. However, the cis UFA were significantly decreased in these groups (p?<?0.05). A markedly increase of indicator in cell membrane viscosity expressed as SFA/UFA was reported in the treated groups (p?<?0.001). A significant increase in the level of malondialdehyde by 38.3 % after 90 days of exposure at 10 mg/l was observed. Compared to control rats, significant liver damage was observed at 10 mg/l of arsenate by increasing plasma marker enzymes after 90 days. It is through the histological investigations in hepatic tissues of exposed rats that these damage effects of arsenate were confirmed. The antioxidant perturbations were observed to be more important at groups treated by the high dose (p?<?0.05). An increase in the level of protein carbonyls was observed in all treated groups (p?<?0.05). The present study provides evidence for a direct effect of arsenite on FA composition disturbance causing an increase of SFA and TFAs isomers, liver dysfunction and oxidative stress. Therefore, arsenate can lead to hepatic damage and propensity towards liver cancer.     

利用缫丝废水处理过程中产生的微生物蛋白制备复合氨基酸

以缫丝废水处理过程中产生的微生物蛋白为原料,采用正交实验分析了采用酸水解、超声波水解、微波水解制备复合氨基酸的最佳工艺条件,并对比了最佳工艺条件下的水解效果.结果表明,酸水解的最佳工艺条件是水解时间2.Oh、固液比(体积比,下同)5∶1、硫酸质量分数50％、水解温度100℃,超声波水解的最佳工艺条件是水解时间0.5h、...     

Photodegradation of new amino acid derivatives suitable for chelating agents in pulp bleaching applications

The purpose of this study was to evaluate photodegradabilities of the following new low-nitrogen chelating agents: N-bis[(carboxymethoxy)ethyl]glycine (compound 1), N-bis[(1,2-dicarboxyethoxy)ethyl]glycine (compound 2) and N-bis[(1,2-dicarboxyethoxy)ethyl]aspartic acid (compound 3). At first photodegradation of these chelating agents as uncomplexed Na-compound 1–3 and Cu(II) complexes were tested, both in lake and distilled water, by exposing them to near-UV region radiation at the range of 315–400 nm. Uncomplexed Na-compounds 2 and 3 were selected to sunlight exposure experiments carried out in lake and distilled water. Compound 3 was also tested in sunlight as Cu and Ca complexes in both solutions. Photodegradation of Na₆-compound 3 in distilled water was studied by exposing it to radiation at the wavelength of 253.7 nm. Photodegradation products were analysed by means of GC-MS (gas chromatography with mass selective detector).

The results demonstrated that compound 1 was quite photostable even as Cu complex while compounds 2 and 3 were found to be photodegradable. Over 90% reduction of compound 3 was achieved during one week and 80% reduction of compound 2 in two weeks' time when they were added as Na salt to lake water and exposed to sunlight. Compound 3 as Cu complex degraded totally in the sunlight in less than one week. In the case of compound 3, the degradation rate decreased depending on the counter cation in the order Cu > Na  Ca. The study demonstrated that photodegradation of Na₆-compound 3 does not result in total mineralization of the compound. A photodegradation pathway for Na₆-compound 3 is proposed.     

Plasma pharmacokinetics of the mycotoxin deoxynivalenol following oral and intravenous administration to sheep

The pharmacokinetics of deoxynivalenol (DON) were studied in sheep after administrating intravenous and oral doses (0.5 and 5.0 mg/kg, respectively). The plasma concentrations were measured using an electron-capture gas chromatographic method. After iv administration DON plasma levels were found to decrease biexponentially, showing a rapid distribution phase (t 1/2 alpha = 12-23 min), followed by a slower elimination phase (t 1/2 beta = 57-78 min). Only trace levels of DON could be detected in plasma 7 hr post-dosing. Further pharmacokinetic data suggest that DON was confined mainly to extracellular fluid, and did not appear to undergo any significant binding or uptake by tissue. After oral dosing, DON was quickly absorbed (t-max 4.0-5.3 hr), but had a systemic bioavailability of only 7.5%; due in part to its rapid and efficient metabolism by rumen microorganisms. Half-life of elimination (t 1/2 beta) was 100-125 min following oral administration, and depending on the animal, required 20-30 hr to be cleared from the system. The metabolic formation of the glucuronide conjugate after iv and oral administration of DON appeared to occur quite efficiently (iv, 21%; oral, 75%), and its elimination half-lives (iv, 150-200 min; oral 6.1-7.1 hr) were considerably longer than that of the parent toxin. Detection in plasma of the de-epoxide metabolite, DOM-1, accounted for only a minor portion of the dose after either dosing regimen (iv, less than 2.0%; oral, less than 0.3%), occurring predominantly as the glucuronide conjugate.     

Heterotrophic community-level physiological profiles of domestic wastewater following treatment by small constructed subsurface flow wetlands.

Seasonal treatment performance of small-surface flow wetlands was evaluated during their second operational year and compared with community-level physiological profiles (CLPP) of the heterotrophic bacterial community obtained from sole-carbon source utilization patterns in BIOLOG GN (Haywood, California) microplates. The CLPP patterns varied significantly by season, indicating reduced functional diversity in the heterotrophic community during warmer months of active plant growth (April through October). Principal component analysis (PCA) suggested that the functional community differed in planted versus unplanted wetlands during the growing season. Wetlands generally improved wastewater quality; however, treatment performance was reduced in the second year. Despite differences in the heterotrophic community suggested by CLPP, treatment efficiency with respect to removal of five-day biochemical oxygen demand or reduction in fecal indicator organisms generally was not significantly changed as a function of growing season or plant treatment.     

Nontransmission of deoxynivalenol (vomitoxin) to milk following oral administration to dairy cows

The absorption of deoxynivalenol (DON; vomitoxin), a trichothecene mycotoxin produced by Fusarium species, was studied in the dairy cow. Serum and milk DON levels were quantitated following a single oral dose of 920 mg DON to each of two lactating cows of similar weight. Maximum blood levels for the two animals following DON administration were 200 and 90 ng/ml serum, occurring at times 4.7 and 3.5 hr, respectively. By 24 hr after dosing only trace levels (less than 2 ng/ml) were still detectable. DON in its conjugated form accounted for 24-46% of the total levels present in serum. Free and conjugated DON were also present in cow's milk, but only extremely low amounts (less than 4 ng/ml) were detected. Detection of DON was carried out utilizing Sep-Pak C18 extraction cartridges for isolation, with additional purification of the sample achieved by passing the extract through a short charcoal/alumina column. The extract was then reacted with N-heptafluorobutyrylimidazole prior to quantitation of the resulting DON-tris-heptafluorobutyrate derivative by combined gas chromatography-quadrupole mass spectrometry, using multiple selected ion monitoring. Detection limits were as low as 1 ng/ml (1 ppb).     

Senna alexandrina extract supplementation reverses hepatic oxidative,inflammatory, and apoptotic effects of cadmium chloride administration in rats

Environmental Science and Pollution Research - Senna alexandrina is traditionally used for its antioxidant and anti-inflammatory properties, but little information is available concerning its...     

Preliminary field study of hepatic porphyrin profiles of Astyanax fasciatus (Teleostei, Characiformes) to define anthropogenic pollution

The implementation of eco-toxicological assessment in South America is presently limited due to significant scientific information gaps concerning native species and their potential use as biomarkers. Recently, a common southern hemisphere fish species, Astyanax fasciatus, has been pointed out as a potential bio-indicator to anthropogenic pollution. This is a small, abundant, Neotropical characid, which is widely distributed from Central America south, to the Rio de la Plata Basin of western Uruguay. Our study found a statistically significant increase of coproporphyrin, uroporphyrin and protoporphyrin concentrations in hepatic tissues of A. fasciatus collected from a stream segment with high anthropogenic disturbance (due mainly to agricultural derivatives and motor vehicle transportation activities). Although the area studied showed differences in up and downstream limno-chemical parameters, these differences were not related to the increase of hepatic porphyrin concentrations. Based on the results of our study, we conclude that A. fasciatus is a good bio-indicator of exposure to environmental contaminants, and we propose that this abundant fish species be considered as a sentinel organism for monitoring potential disturbances to freshwater ecosystems.     

Metabolic fate and elimination in milk, urine and bile of deoxynivalenol following administration to lactating sheep

Using a combination of radioisotopic counting and chromatographic detection techniques, the kinetics and metabolic fate of deoxynivalenol (DON) in plasma, urine and bile were studied in lactating sheep, as was the transmission of residues to milk. Following intravenous administration, the plasma clearance of 14C-DON-derived radioactivity was rapid and followed a tri-phasic decay curve comprised of a bi-exponential decrease in DON (rapid distribution phase, t1/2 alpha = 16.2 min; slower elimination phase t1/2 beta = 66.5 min) and the formation and elimination (t1/2 beta = 188.0 min) of its major plasma metabolite, DON-glucuronide conjugate, which accounted for 13% of the plasma radioactivity levels. DON was rapidly cleared from the body by metabolism to 7 possible metabolites, which were excreted essentially in the urine (91%) and to a lesser extent in the bile (6%). Most (67%) of the recovered radioactivity was in the form of the glucuronide conjugates of DON (54%) and the de-epoxide metabolite, DOM-1 (13%). Excretion of unmetabolized DON accounted for 11%. The remaining recovered dose (18%) comprised of minor amounts of DOM-1 (6%), DON-sulfate conjugate (2%) and 3 unidentified radioactive components (10%). Studies on the presence of DON-derived residues in milk indicated that, relative to the dose, only trace amounts were transmitted following either oral or iv administration of the toxin.     

Ambient air pollution induced changes in amino acid pattern of phloem sap in host plants-relevance to aphid infestation

In pollution exclusion experiments on the verge of a widely-used motorway, it has been shown that roadway emissions increase the abundance of the aphid Aphis fabae Scop. on two different host plants, Viburnum opulus L. and Phaseolus vulgaris L. Analysis of phloem sap of excised leaves revealed on increase in almost all of the detected amino acids due to ambient air pollution. To investigate the significance of these changes to aphid development, the patterns analyzed were translated into artificial diets, representing the amino acid composition either of filtered air or ambient air host plants. On 'ambient air' diets, the larvae were significantly larger at birth compared to the progeny on 'filtered air' diets. Also the mean relative growth rates (MRGR) of larvae reared on 'ambient air' diets were significantly increased. At the same time, a conspicuous shorter development time of the larvae could be observed on 'ambient air' diets.     

Elimination kinetics of perfluorohexanoic acid in humans and comparison with mouse,rat and monkey

Major fluorinated chemical manufacturers have developed new short-chain per- and polyfluorinated substances with more favorable environmental, health and safety profiles. This study provides the first evaluation of the elimination half-life of perfluorohexanoic acid (PFHxA) from the blood of humans. PFHxA biomonitoring data were obtained from a recently published study of professional ski wax technicians. These data were analyzed to provide estimates of the apparent half-life of PFHxA from humans, and comparisons were made with kinetic studies of PFHxA elimination from mice, rats and monkeys. The apparent elimination half-life of PFHxA in highly exposed humans ranged between 14 and 49 d with a geomean of 32 d. The half-lives of PFHxA in mice, rats, monkeys and humans were proportional to body weight with no differences observed between genders, indicating similar volumes of distribution and similar elimination mechanisms among mammalian species. Compared to long-chain perfluoroalkyl acid analogs, PFHxA is rapidly cleared from biota. The consistent weight-normalized elimination half-lives for PFHxA in mammalian species indicates that results obtained from animal models are suitable for establishment of PFHxA benchmark dose and reference dose hazard endpoints for use in human risk assessments.     

Effect of cadmium on free amino acid, glutathione and ascorbic acid concentrations in two barley genotypes (Hordeum vulgare L.) differing in cadmium tolerance

Hydroponic experiment was carried out to study the effect of three Cd levels on glutathione (GSH), free amino acids (FAA), and ascorbic acid (ASA) concentration in the different tissues of 2 barley cultivars with different Cd tolerance. Cadmium concentration in both roots and shoots increased with external Cd level, while biomass and ASA concentration declined, and Wumaoliuling, a Cd-sensitive genotype was more affected than ZAU 3, a Cd-tolerant genotype. The effect of Cd on GSH concentration was dose- and time-dependent. In the 5 d exposure, root GSH concentration increased in 0.5 microM Cd treatment compared with control, but decreased significantly in 5 microM Cd treatment, irrespective of genotypes. However, in the 10 d exposure, GSH concentration in all plant tissues decreased with increasing Cd levels in the culture medium, and Wumaoliuling was much more affected than ZAU 3. Cadmium treatment greatly altered FAA concentration and composition in plants. The effect of Cd on glutathione (Glu) concentration in roots varied with genotypes. ZAU 3 showed a steady increase in root Glu concentration in both 0.5 and 5 microM Cd treatments, while Wumaoliuling was decreased by 38.0% in 5 microM Cd treatment, compared with the control. The results indicate that GSH and ASA are attributed to Cd tolerance in barley plants, and the relative less reduction in GSH concentration in ZAU 3 under Cd stress relative to the control may account for its higher Cd tolerance.     

Ameliorative effects of deferiprone and tetraethylammonium salt of salinomycinic acid on lead-induced toxicity in mouse testes

Environmental Science and Pollution Research - In this study, we compare the effects of deferiprone (Def) and tetraethylammonium salt of salinomycinic acid (Sal) on lead (Pb)-induced toxicity in...     

Distribution and toxicity of monosodium methanearsonate following oral administration of the herbicide to dairy sheep and goats

Iranian fat-tailed sheep and dairy goats were administered the herbicide monosodium methanearsonate orally at a dose of 10 mg. MSMA (as arsenic) per kg. of body weight. The concentration time curves of MSMA in the blood of sheep and goats followed a first order composite exponential equation of the form: Cb(t) = Ae- alpha t + Be- beta t - C degrees be-kat. Absorption, distribution and elimination of MSMA, therefore, corresponds to an open two-compartment model. Arsenic from MSMA was readily absorbed from gastrointestinal tract and distributed in the body fluids and the various tissues. Approximately 90% of the arsenic was excreted in the urine within 120 hrs and small amounts were also recovered in feces. Arsenic accumulation in the tissues was low and urinary excretion was the most important exit route. Arsenic concentrations in milk were low when compared to the controls, which indicates that arsenic is not excreted in the milk to significant levels. The absorption, distribution and overall elimination rate constants for the two animal species studied were statistically different at the 0.95 level of confidence which indicates that there are apparently differences in MSMA metabolism by sheep and goats.