Salinity influences glutathione S-transferase activity and lipid peroxidation responses in the Crassostrea gigas oyster exposed to diesel oil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In vitro exposure to fullerene C60 influences redox state and lipid peroxidation in brain and gills from Cyprinus carpio (Cyprinidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Implications of groundwater weathered profile interactions to the mobilization of radionuclides

This study reports the nature and extent of open-system interaction between groundwater and a weathered profile developed in the high grade thorium and REE ore body in Morro do Ferro, Pocos de Caldas plateau. The radioelement mobility in the shallow oxidizing environment was considered by using chemical data in conjunction with U-234/U-238, Ra-226/Th-230, Th-230/U-234, Th-228/Th-232, Ra-228/Th-232 and Th-230/Ra-228 activity ratios (AR's) for borehole spoil and groundwater samples.Recharging groundwater from the studied borehole has low salinity values, with total dissolved solids content of 14.7 mg/l and total ionic strength of 0.00018. The ratio of the weight of dissolved radioelement per unit volume of solution to the weight of radioelement in solid phase per unit weight of solid phase showed that the radioelement solubility in the studied waters varied according to the following order: radium> uranium >thorium.U-234/U-238 AR's less than 1 were measured in solid phase and can justify the enhancement of U-234 in solution. Ra-226/Th-230 AR's greater than 1 and Th-230/U-234 AR'S less than 1 were evaluated between 20 and 27 m in depth, where a 2.1-m thick magnetite dike was intersected. These ratios could be justified by deposition of U and Ra associated with Fe-Mn oxides and kaolinite, where mineral saturation indices evaluated from the available data confirm this possibility. Covariations among disequilibria involving Th-228/(228) Ra and Ra-228/Th-232 AR's showed the preferential removal of Ra-228 relative to Tn isotopes, Th-228 and Th-232. The recent deposition of radium within the timescale of at least the last 35 years also is suggested. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

The membranotropic activity of N-terminal peptides from the pore-forming proteins sticholysin I and II is modulated by hydrophobic and electrostatic interactions as well as lipid composition

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Labaditin, a cyclic peptide with rich biotechnological potential: preliminary toxicological studies and structural changes in water and lipid membrane environment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Loading of praziquantel in the crystal lattice of solid lipid nanoparticles Studies by DSC and SAXS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nymphal development, lipid content, growth and weight gain of Nezara viridula (L.) (Heteroptera: Pentatomidae) fed on soybean genotypes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Lipid peroxidation, antioxidant enzymes and glutathione levels in human erythrocytes exposed to colloidal iron hydroxide in vitro

The free form of the iron ion is one of the strongest oxidizing agents in the cellular environment. The effect of iron at different concentrations (0, 1, 5, 10, 50, and 100 µM Fe3+) on the normal human red blood cell (RBC) antioxidant system was evaluated in vitro by measuring total (GSH) and oxidized (GSSG) glutathione levels, and superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and reductase (GSH-Rd) activities. Membrane lipid peroxidation was assessed by measuring thiobarbituric acid reactive substance (TBARS). The RBC were incubated with colloidal iron hydroxide and phosphate-buffered saline, pH 7.45, at 37oC, for 60 min. For each assay, the results for the control group were: a) GSH = 3.52 ± 0.27 µM/g Hb; b) GSSG = 0.17 ± 0.03 µM/g Hb; c) GSH-Px = 19.60 ± 1.96 IU/g Hb; d) GSH-Rd = 3.13 ± 0.17 IU/g Hb; e) catalase = 394.9 ± 22.8 IU/g Hb; f) SOD = 5981 ± 375 IU/g Hb. The addition of 1 to 100 µM Fe3+ had no effect on the parameters analyzed. No change in TBARS levels was detected at any of the iron concentrations studied. Oxidative stress, measured by GSH kinetics over time, occurs when the RBC are incubated with colloidal iron hydroxide at concentrations higher than 10 µM of Fe3+. Overall, these results show that the intact human RBC is prone to oxidative stress when exposed to Fe3+ and that the RBC has a potent antioxidant system that can minimize the potential damage caused by acute exposure to a colloidal iron hydroxide in vitro.

Effect of L-arginine, dimercaptosuccinic acid (DMSA) and the association of L-arginine and DMSA on tissue lead mobilization and blood pressure level in plumbism

Lead (Pb)-induced hypertension is characterized by an increase in reactive oxygen species (ROS) and a decrease in nitric oxide (NO). In the present study we evaluated the effect of L-arginine (NO precursor), dimercaptosuccinic acid (DMSA, a chelating agent and ROS scavenger), and the association of L-arginine/DMSA on tissue Pb mobilization and blood pressure levels in plumbism. Tissue Pb levels and blood pressure evolution were evaluated in rats exposed to: 1) Pb (750 ppm, in drinking water, for 70 days), 2) Pb plus water for 30 more days, 3) Pb plus DMSA (50 mg kg-1 day-1, po), L-arginine (0.6%, in drinking water), and the combination of L-arginine/DMSA for 30 more days, and 4) their respective matching controls. Pb exposure increased Pb levels in the blood, liver, femur, kidney and aorta. Pb levels in tissues decreased after cessation of Pb administration, except in the aorta. These levels did not reach those observed in nonintoxicated rats. All treatments mobilized Pb from the kidney, femur and liver. Pb mobilization from the aorta was only effective with the L-arginine/DMSA treatment. Blood Pb concentrations in Pb-treated groups were not different from those of the Pb/water group. Pb increased blood pressure starting from the 5th week. L-arginine and DMSA treatments (4th week) and the combination of L-arginine/DMSA (3rd and 4th weeks) decreased blood pressure levels of intoxicated rats. These levels did not reach those of nonintoxicated rats. Treatment with L-arginine/DMSA was more effective than the isolated treatments in mobilizing Pb from tissues and in reducing the blood pressure of intoxicated rats.

Physiological responses of Nile tilapia, Oreochromis niloticus, fed vitamin C- and lipid-supplemented diets and submitted to low-temperature stress

Water temperature alterations can determine harmful physiological modifications in fish, which should be prepared to cope with this, and nutrition strategies seem to be essential. This study evaluated the effects of different levels of vitamin C and lipids on physiological responses of Nile tilapia, Oreochromis niloticus, submitted to temperature stress. There were two phases: Phase I - preparing fish to store vitamin C and lipid at appropriate temperature, and Phase II - evaluating the contributions these reserves make to fish physiology under low-temperature stress. The experiment used a 3 x 2 factorial design with three vitamin C levels (300, 600, and 1200 mg/kg diet) and two lipid levels (8.0 and 12.0%), plus absence of nutrient test and a diet of 6.0% lipids and 125.0 mg/kg vitamin C. In Phase I, 192 fish were kept at 26.0 +/- 1.0 C for 112 d, and in Phase II, 48 fish were kept at 18.0 +/- 0.5 C for 32 d and at 15.0 +/- 0.5 C for 11 d. Fish fed C0L0 diet showed lower erythrocytes values in both phases; higher vitamin C supplement determined higher red blood cell (RBC) number and higher hematocrit (Htc) (Phase II); Htc was significantly lower in Phase II; after temperature stress, fish fed C0L0 diet had higher mean corpuscular volume, lower hemoglobin corpuscular concentration, and significantly lower vitamin C concentration in the liver; and higher supplementation determined a higher concentration in the liver (Phases I and II). Higher plasmatic cortisol concentration was seen in fish fed C0L0 diet. In conclusion, our results show that the absence of vitamin C in diets impairs RBC formation and does not enable fish to cope with stress; excess vitamin C is efficient in mitigating stress and 600 mg/kg diet is economic and physiologically sufficient to prepare fish for coping with low-temperature stress. Lipid supplementation does not determine alterations in stress biochemical parameters.

Combined corneal lipid and calcium degeneration in a dog with hyperadrenocorticism: a case report

Corneal degeneration may occur with a deposition of lipids or calcium, or both. Calcareous and lipid degeneration may be either primary or secondary, associated with systemic diseases such as primary hyperlipidemia, hyperlipidemia associated with hyperadrenocorticism, and hypothyroidism. The authors report a case of bilateral corneal lipid and calcium degeneration in a 7-year-old female Poodle with hyperadrenocorticism. The condition worsened with Lysodren(R) therapy but responded to surgical excision.

Effects of 2 or 5 consecutive exercise days on adipocyte area and lipid parameters in Wistar rats

Background: Exercise has been prescribed in the treatment and control of dyslipidemias and cholesterolemia, however, lipid responses to different training frequencies in hypercholesterolemic men have been inconsistent. We sought to verify if different frequencies of continuous moderate exercise (2 or 5 days/week, swimming) can, after 8 weeks, promote adaptations in adipocyte area and lipid parameters, as well as body weight and relative weight of tissues in normo and hypercholesterolemic adult male rats.Methods: Normal cholesterol chow diet or cholesterol-rich diet (1% cholesterol plus 0.25% cholic acid) were freely given during 8 weeks to the rats divided in 6 experimentals groups: sedentary normal cholesterol chow diet (C); sedentary cholesterol-rich diet (H); 5x per week continuous training normal cholesterol chow diet (TC5) and cholesterol-rich diet (TH5); 2x per week continuos traning normal cholesterol chow diet (TC2) and cholesterol-rich diet (TH2).Results: No changes were observed in lipid profile in normal cholesterol chow diet, but both 2 a 5 days/week exercise improved this profile in cholesterol-rich diet. Body weight gain was lower in exercised rats. Decrease in retroperitoneal and epididymal relative weights as well as reductions in adipocyte areas under all diets types were observed only in 5 days/week, while 2 days/week showed improvements mainly in cholesterol-rich diet rats.Conclusion: Our results confirm the importance of exercise protocols to control dyslipidemias and obesity in rats. The effects of 5 days/week exercise were more pronounced compared with those of 2 consecutive days/week training.

Impact of the training program on lipid profile and cardiac health

The aim of this study was to investigate the effects of training programs on serum lipid profile and myocardial oxidative stress. Male Wistar rats (2 mo-old) were divided into three groups (n=8): sedentary (S), loadless trained (T) and trained-overload 2% body weight (TL). T and TL were trained through swimming for 9 weeks. T and TL rats had increased myocardial lipoperoxide (TBA) and lipid hydroperoxide (HP), whereas HP was higher in TL than in T animals. Superoxide dismutase (SOD) activities were lowest in TL. Myocardial glutathione peroxidase (GSH-Px) was lower in TL than in T and S rats. TL decreased HDL-cholesterol and increased LDL-cholesterol. The serum lactate dehydrogenase and TBA were increased, while SOD and GSH-Px activities were decreased in TL rats. Loadless training was able to improve HDL-cholesterol and to reduce LDL-cholesterol. In conclusion, the loadless training program induced beneficial effects on lipid profile, while overload training induced dyslipidemic profile that was associated with serum oxidative stress. The overload training program was deleterious relative to loadless training program, increasing myocardial oxidative stress.

Growth and metabolism of pacu (Piaractus mesopotamicus Holmberg 1887) juveniles fed diets containing different protein, lipid and carbohydrate levels

To verify the potential of lipids and carbohydrates to spare dietary protein and to understand the intermediary metabolism of interaction of these nutrients in pacu juveniles, an experiment was carried out to evaluate pacu physiological and performance parameters. The experimental design was completely randomized with 12 treatments in a 2 x 2 x 3 factorial arrangement, consisting of diets containing two digestible protein levels (200 and 230 g kg(-1) PD), two lipid levels (40 and 80 g kg(-1)) and three carbohydrate levels (410, 460 and 500 g kg(-1)). Fish-fed 230 g kg(-1) digestable protein (DP) showed increased glycaemia, decreased hepatic glycogen, as well as a smaller intake index and better feed conversion ratio. The higher dietary lipid level (80 g kg(-1)) reduced protein intake and serum protein concentration, increased liver and body fat content, but did not affect growth. At a lipid level of 80 g kg(-1), the increase in dietary carbohydrate levels promoted greater weight gain (WG), crude protein intake (CPI) and better feed conversion ratio (FCR). For fish fed diets containing 40 g kg(-1) lipid, the best energy-productive values (EPV) were obtained at 460 g kg(-1) carbohydrate. Increased levels of the main nutrients in the diets reduced the levels of serum triglycerides, while the increase in energy concentration increased the hepatosomatic (HSI) and glycaemia index values. Pacu used lipids as effectively as carbohydrates in the maximization of protein usage, as long as dietary protein was at a level of 230 g kg(-1) DP. The physiological parameters indicated that the best balance between the DP, dietary lipid and carbohydrate levels within the ranged this trial was obtained at 230, 40 and 460 g kg(-1), respectively, without lower growth.