Changes in the regulation and activity of glutathione redox system, and lipid peroxidation processes in short-term aflatoxin B1 exposure in liver of laying hens.

The purpose of this study was to investigate the short-term (48 hr) effects of feeding aflatoxin contaminated diet (170.3 µg/kg AFB1) in 49-week-old laying hens. Liver samples were taken at 12-hr intervals. Feed intake, body weight, absolute and relative liver weight were the same in groups. However, there was no feed intake during both dark periods (between 12nd to 24th and 36th to 48th hours of the experiment); therefore, aflatoxin intake was also negligible. Markers of initial phase of lipid peroxidation, conjugated dienes and trienes did not change as effect of aflatoxin, but terminal marker, malondialdehyde content was significantly higher at 12 hr as effect of aflatoxin. No significant difference was found in reduced glutathione concentration and glutathione peroxidase activity between the groups. Expression of glutathione peroxidase 4 gene (GPX4) was significantly reduced due to aflatoxin treatment at 12 and 24 hr, but induced later, while glutathione reductase gene (GSR) expression was significantly lower at 24 hr and glutathione synthetase gene (GSS) in aflatoxin-treated group at 12 hr. The results suggest that aflatoxin induced oxygen-free radical formation, but it did not reach critical level during this short period of time to cause activation of the expression of glutathione system.

Effect of nano-sized, elemental selenium supplement on the proteome of chicken liver.

The nano-sized (100-500 nm) selenium has higher bioavailability and relatively lower toxicity compared to other selenium forms. The objective of the present study was to compare liver proteome profiles of broiler chicken fed with control diet without Se supplementation and diet supplemented with nano-Se with 4.25 mg/kg DM. Differential proteome analyses were performed by two-dimensional gel electrophoresis (2D-PAGE) followed by tryptic digestion and protein identification by liquid chromatography-mass spectrometry (LC-MS). Seven hundred and eight spots were detected, and 18 protein spots showed significant difference in their intensity (p < 0.05) between the two groups. In response to nano-Se supplementation, the expression of 8 proteins was higher, and 5 proteins were lower in nano-Se supplemented group compared to control group. The functions of the differentially expressed proteins indicate that the high dose of selenium supplementation induced a dietary stress. Selenium supplementation may influence the metabolism of fatty acids and carbohydrates and antioxidant system, and increase the quantity of cytoskeletal actin and the expression of actin regulatory protein as well.

Short-term effects of T-2 toxin exposure on some lipid peroxide and glutathione redox parameters of broiler chickens.

The purpose of this study was to investigate the short-term effects of T-2 toxin exposure (3.09 mg/kg feed) on lipid peroxidation and glutathione redox system of broiler chicken. A total of 54 Cobb 500 cockerels were randomly distributed to two experimental groups at 21 days of age. Samples (blood plasma, red blood cell, liver, kidney and spleen) were collected every 12 h during a 48-h period. The results showed that the initial phase of lipid peroxidation, as measured by conjugated dienes and trienes in the liver, was continuously, but not significantly higher in T-2 toxin-dosed birds than in control birds. The termination phase of lipid peroxidation, as measured by malondialdehyde, was significantly higher in liver and kidney as a result of T-2 toxin exposure at the end of the experimental period (48th hour). The glutathione redox system activated shortly after starting the T-2 toxin exposure, which is supported by the significantly higher concentration of reduced glutathione and glutathione peroxidase activity in blood plasma at 24 and 48 h, in liver at 12, 24 and 36 h, and in kidney and spleen at 24 h. These results suggest that T-2 toxin, or its metabolites, may be involved in the generation of reactive oxygen substances which causes an increase in lipid peroxidation, and consequently activates the glutathione redox system, namely synthesis of reduced glutathione and glutathione peroxidase.

Body mass related variations in the polar lipid fatty acyl chain composition of the mammalian lung and alveolar surfactant.

In nine mammalian species (mouse - cattle: 21.5 g-503 kg) lung total phospholipids (PL), alveolar surfactant phosphatidylcholine (PC) and sphingomyelin (SM) fatty acyl (FA) chain composition was tested relating to body mass (BM) and resting respiratory rate (RRR) associated adaptations. In PL, PC and SM oleic acid (C18:1 n9) provided negative correlations with RRR. Palmitic acid (C16:0) was strongly, positively correlated with RRR in the pulmonary PLs, and myristic (C14:0) acid correlated positively with RRR in the surfactant PCs. In pulmonary PLs negative allometry was found for myristic, palmitic, palmitoleic (C16:1 n7) and docosahexaenoic (C22:6 n3) acids and total saturation, while oleic (C18:1 n9), alpha-linolenic (C18:3 n3) and gondoic (C20:1 n9) acids, total n9 FA s and monounsaturation increased allometrically. In surfactant PC FA s palmitic acid provided negative, while oleic acid and monounsaturation positive allometry; the average FA chain length (ACL) was identical in all species. Surfactant SM FA composition was fully species independent for palmitic and arachidonic acids, total saturation, monounsaturation and ACL. The in vivo lipid peroxidation rate was species independent. The variability of lung PLs was consonant with the "membrane pacemakers theory", while surfactant PC composition was mostly related to RRR.

Negative allometry of docosahexaenoic acid in the fowl lung and pulmonary surfactant phospholipids.

In a recent study (Comp. Biochem. Physiol. B. (2010)155: 301-308) we reported that the fatty acids (FA) of the avian (7 species) total lung phospholipids (PL) (i.e. lung parenchyma and surfactant together) provide allometric properties. To test whether this allometric scaling also occurs in either of the above components, in six gallinaceous species, in a body weight range from 150 g (Japanese quail, Coturnix coturnix japonica) to 19 kg (turkey, Meleagris gallopavo) the PL FA composition (mol%) was determined in the pulmonary surfactant, in native and in thoroughly lavaged lungs (referred to as lung parenchyma). In all three components docosahexaenoic acid (DHA) showed significant and negative allometric scaling (B = -0.056, -0.17 and -0.1, respectively). Surfactant PLs provided further negative allometry for palmitic acid and the opposite was found for palmitoleate and arachidonate. In the lung parenchymal PLs increasing body weight was matched with shorter chain FAs (average FA chain length) and competing n6 and n3 end-product fatty acids (positive allometry for arachidonic acid and negative for DHA). Negative allometric scaling was found for the tissue malondialdehyde concentration in the native and lavaged lungs (B = -0.1582 and -0.1594, respectively). In these tissues strong correlation was found between the MDA concentration and DHA proportion (r = 0.439 and 0.679, respectively), denoting the role of DHA in shaping the allometric properties and influencing the extent of in vivo lipid peroxidation of membrane lipids in fowl lungs.

Effects of oral L-carnitine, L-lysine administration and exercise on body composition and histological and biochemical parameters in pigeons.

The purpose of this study was to examine whether L-carnitine and its precursor L-lysine could have any beneficial effect in racing pigeons, and if so, whether this effect is influenced by the extent of exercise (short-distance flight: 135 km vs. long-distance flight: 580 km). Birds were divided into seven groups of animals. Group 1: negative control, no flight, no treatment, Group 2: positive control, placebo treatment before the short-distance flight, Group 3: 200 mg/day L-carnitine treatment before the short-distance flight, Group 4: 400 mg/day L-lysine treatment before the short-distance flight, Group 5: positive control, placebo treatment before the long-distance flight, Group 6: 200 mg/day L-carnitine treatment before the long-distance flight, Group 7: 400 mg/day L-lysine treatment before the long-distance flight. L-carnitine, L-lysine and distilled water (placebo) were orally administered (tube feeding) for 7 days before flight. Just after returning home, blood samples were collected and analyzed for glucose, fructosamine, cholesterol, triglycerides and thiobarbituric acid reactive substances. Pigeons were euthanized using carbon dioxide as an inhalation agent, and the whole body was subjected to proximate analysis. The status at arrival was referred to as a basis for comparison. Sex did not affect the measured parameters. As a result of the L-carnitine and L-lysine administrations, the body fat mobilization was higher during the 580 km flight, whereas no changes were noted during the 135 km flight. The main changes in the measured blood parameters were caused by the extent of exercise. This experiment considered the extent of exercise as a factor potentially modulating L-carnitine supplementation effects. In conclusion, flight distance affected several parameters but the supplements of L-carnitine and L-lysine were not effective in the tested situations.

Effect of dietary fatty acid pattern on growth, body fat composition and antioxidant parameters in broilers.

The effects of dietary fat supplementation on performance, fatty acid (FA) composition of tissues and antioxidant defence system of broilers were studied. Male broilers were placed in 20 floor pens (60 broilers per pen). The broilers were fed by diets with added different energy sources: lard (L); sunflower oil (SFO); soybean oil (SBO); and linseed oil (LSO). The treatments did not modify significantly growth performance and feed intake of the broilers. There was no effect of dietary FA pattern on reduced glutathione level and glutathione peroxidase activity of plasma, erythrocyte and liver samples. However, higher PUFA content of the diet resulted in a significant increase in malondialdehyde level of erythrocytes and liver. The broilers fed LSO diet more effectively maintained their antioxidant status with enhanced plasma radical scavenger capacity. FA composition in tissues reflected the FA pattern of the diets, although proportion of FAs with four or more double bonds was metabolic specific. LSO diet increased the level of C18:3, C20:5 and C22:6 in tissue lipids in relation to L, SFO and SBO diets. Significantly increased plasma radical scavenging capacity in concert with the enhanced C20:5 and C22:6 proportion in liver and muscle during LSO feeding indicate metabolic changes to counteract the oxidative injury. This may be related to the compounds produced after different biochemical pathways of n-6 and n-3 FAs.

Effect of feeding T-2 toxin contaminated feed on the utilisation of vitamin E in chickens.

The purpose of the present study was to investigate the effect of experimental T-2 toxin load (2.35 mg/kg of feed) and vitamin E supply in the drinking water (10.5 mg/bird/day) on vitamin E levels of the blood plasma and liver in broiler chickens in a 14-day experiment. It was found that T-2 toxin load did not influence vitamin E content of the blood plasma except at day 3 after the toxin load when a moderate increase was detected in plasma vitamin E. No significant changes were found in vitamin E content of the liver. The simultaneous use of high-dose vitamin E supplementation and T-2 toxin load caused a significantly higher plasma vitamin E content but the changes were less expressed in the group subjected to T-2 toxin load. Vitamin E supply also resulted in a marked and significant increase in vitamin E concentrations of the liver on days 3 and 7 even in the T-2 loaded group, but this concentration significantly decreased thereafter. The results show that T-2 contamination of the diet has an adverse effect on the utilisation of vitamin E in broiler chickens.

Effects of ochratoxin A on some production traits, lipid peroxide and glutathione redox status of weaned piglets.

The effect of feeding ochratoxin A (OTA) contaminated diet (379.6 and 338.1 microg/kg in starter and grower diets) on production traits, lipid peroxidation and some parameters of the glutathione redox system were investigated in weaned piglets over a seven-week period. Feed intake and feed conversion ratio (FCR) did not differ significantly, but in the first phase (0-28 days) the daily weight gain was significantly lower in the piglets fed the OTA-contaminated diet. Lipid peroxidation, as measured by the amount of malondialdehyde, glutathione content and glutathione peroxidase activity, did not change significantly in the blood plasma and red blood cell haemolysate in the OTA-loaded group, while malondialdehyde content increased significantly in the liver and markedly but not significantly in the kidney of piglets fed OTA-contaminated feed. Glutathione content did not differ significantly in the studied organs of the two groups while glutathione peroxidase activity of the OTA-loaded animals was significantly lower both in the liver and in the kidney. The results suggest that the use of feed-stuffs contaminated with low levels of OTA for seven weeks did not cause marked differences in the production traits or in lipid peroxidation and amount or activity of the glutathione redox system in the blood plasma, red blood cells and kidney, while significant changes occurred in the liver homogenate.

Investigation of lipid peroxide and glutathione redox status of chicken concerning on high dietary selenium intake.

This study was designed to investigate the effects of excess (24.5 mg Se/kg feed) inorganic and organic dietary selenium supplementation on 3-week-old broilers. The experiments lasted 4 days. Intensity of lipid peroxidation processes (malondialdehyde, MDA) and the amount (reduced glutathione, GSH) and activity (glutathione peroxidase activity, GSHPx) of gluathione redox system were measured in blood plasma, red blood cell hemolysate and liver. Voluntary feed intake in the selenium-treated groups reduced remarkably. Elevated GSH concentration and GSHPx activity were measured in plasma and liver of both selenium-treated groups compared to the untreated control and the 'pair-fed' controls. The lipid peroxidation processes in the liver showed higher intensity than the control due to both selenium treatment. The applied dose of selenite and selenomethionine does not inhibit, but even improves the activity of glutathione redox system in the liver during the early period of selenium exposure.

Free radicals, lipid peroxidation and the antioxidant system in the blood of cows and newborn calves around calving.

The oxidative stress of birth in cattle (Bos taurus) was evaluated by measuring steady state concentration of free radicals in whole blood, rate of lipid peroxidation and activity of antioxidant enzymes in erythrocytes, antioxidant capacity of blood plasma in 14 calves at birth and four times after birth until 3 weeks of age and also in their mothers at calving. The same parameters were also measured in 58 dairy cows before calving, at parturition and after calving. Free radical concentration in the blood of newborn calves was higher than in cows confirming that birth means oxidative stress for calves. Red blood cell malondialdehyde in calves was the highest at birth and following the first solid feed intake at the third week. Superoxide dismutase activity increased in calves during the first three weeks of life. Ferric reducing ability of plasma was higher in calves at birth than in cows and decreased thereafter. Higher superoxide dismutase activity in red blood cells and lower ferric reducing ability of plasma in dairy cows was found at calving compared to the average of all pre- and post-calving results. We conclude that the blood of newborn calves is well prepared to deal with the oxidative stress of birth, and that such a stress is present even when some fingerprint markers of redox imbalance show no apparent alterations. Stress of calving has minor effects on the antioxidant system of cows.

Oral administration of fumonisin B1 and T-2 individually and in combination affects hepatic total and mitochondrial membrane lipid profile of rabbits.

Weaned rabbits were fed diets contaminated with 2 mg/kg diet T-2 toxin alone, or 10 mg/kg diet fumonisin B1 (FB1) alone, and both toxins in combination (2 + 10 mg/kg, respectively) compared to a toxin-free control diet. Samplings were performed after 4 weeks (blood and liver). Bodyweight of T-2-fed group was lower after 4 weeks; the liver weight was increased dramatically (threefold of control). Liver total phospholipids (PLs) provided slight alterations in the fatty acid (FA) composition; all three toxin-treated groups showed a decrease in palmitoleic acid (C16:1 n7) proportion. In the liver mitochondrial PL FA composition, margaric acid (C17:0) proportion decreased in the separated toxin treatments compared to the combined setting. Oleic acid (C18:1 n9) proportion was increased and arachidonic acid (C20:4 n6) was decreased in the FB1-treated group, while docosapentaenoic acid (C22:5 n3) was decreased in the separated treatments. The total monounsaturation was significantly higher in the FB1 group's mitochondrial PL FA profile. After 4 weeks, all toxin treatments decreased the blood plasma reduced glutathione and glutathione peroxidase activity, and FB1 increased the plasma sphinganine/sphingosine ratio. Both mycotoxins seem to cross the hepatocellular and the hepatic mitochondrial membrane, without drastic membrane disruption, as assessed from the PL FA composition, but inducing detectable lipid peroxidation.

Differential utilization of hepatic and myocardial fatty acids during forced molt of laying hens.

Feed was totally withdrawn from laying hens (n = 30, Hy-Line Brown, 608 d of age, 2.04 +/- 0.07 kg of mean BW) to induce molting. Ten birds were slaughtered on d 0 and 12, and the hepatic and myocardial triacylglycerol (TAG) and phospholipid (PL) fatty acid composition, as well as the tissue malondialdehyde (MDA) and reduced glutathione (GSH) concentrations were determined. The liver TAG and PL contents decreased by 24.3 and 16.1%, respectively, whereas the myocardial TAG content increased by 12%, and the PL decreased by 22%. Liver TAG fraction has been found to selectively retain arachidonic and docosahexanoic acids. Hepatic PL fatty acids were markedly affected by fasting; these changes reflected an altered PL metabolism, primarily degradation. Liver TAG compensated for the absence of dietary fatty acids, because we found practically no qualitative alteration in myocardial TAG. The lipid peroxide status, as measured with MDA content was, accordingly, increased in the liver tissue only. In the myocardial PL fatty acids, preferred conservation of arachidonic acid was shown, and it was hypothesized that energy deprivation of cardiomyocytes strongly improved PL degradation in fasting laying hens and influenced PL homeostasis. Generally the physiological recovery from forced molting associated with fasting is complete; however, the use of total feed withdrawal methods should be reevaluated.

Developmental dynamics of some blood biochemical parameters in the growing turkey (Meleagris gallopavo).

Blood serum clinical biochemical parameters of fasted BUT Big 8 male turkeys were determined at the ages of 3 days, 4, 8, 12, 16 and 20 weeks, for a follow-up of the developmental changes of some serum metabolites, enzymes and ions. The serum protein content (total protein, albumin, globulin) increased with age, indicating also the moulting-associated metabolic changes in the age interval from the 8th to the 12th weeks. Creatinine was shown to have a peak at 3 days of age (role of muscle activity in thermogenesis), while urate concentration sensitively reflected the dietary protein amount. Serum triglycerides peaked at the time of yolk catabolism, while cholesterol was shown to indicate the moulting, as was serum malondialdehyde. Serum sodium content increased throughout the study. Alanine aminotransferase and aspartate aminotransferase activities increased along the ontogeny, while alkaline phosphatase activity decreased in parallel with the growth. Serum creatine kinase activity showed an over one-magnitude increase. General metabolic and enzymatic alterations were characteristic and applicable for the description of the ontogenetic development of a precocial (post-hatch triglyceride peak), large bodied, meat-type (lactate dehydrogenase, continuously increasing creatine kinase) bird species.

Effect of different dietary fat sources on production traits, lipid peroxide status and on the glutathione redox system in African catfish [Clarias gariepinus (Burchell)] fingerlings. Short communication.

Lipids are used to provide the energy to cover the metabolic needs and to provide essential fatty acids, which are important for membrane function [12]. Fats may contain high level of long chain polyunsaturated fatty acids, which are prone to peroxidation [8] and will interact with the antioxidant defense system [1]. There is contradiction in the literature about whether the intake of fish oil enhance [7] or deplete [4] tissue antioxidant defenses and the glutathione redox system in different organisms. The aim of the present study was to examine the effects of different dietary oils on parameters of the lipid peroxide state and the glutathione redox system in C. gariepinus fingerlings.

Investigations concerning vitamin A transport in rheumatic diseases.

The investigation concerned changes in vitamin A derivatives (retinol and retinyl) content in serum of patients suffering from two types of rheumatic diseases--rheumatoid arthritis (RA) and osteoarthrosis. Healthy women of similar age served as control. It was found that the retinol content of the serum in the group suffering from RA was significantly (P less than 0.001) lower than that of the control group, while in the group suffering from osteoarthrosis it was significantly higher (P less than 0,01). The serum retinol content of the group with RA was similar and was not an effect of the corticosteroid treatment. Significant differences were found (P less than 0,01) between the groups suffering from RA and osteoarthrosis in the serum content of the retinol. The retinyl content of the serum showed a significant (P less than 0.05) difference between the groups afflicted with RA and osteoarthrosis.

Investigations on vitamin E and lipid peroxide status in rheumatic diseases.

Patients of both sexes suffering from two types of rheumatic diseases-- rheumatoid arthritis and osteoarthrosis--were examined. Healthy volunteers of similar age served as controls. No significant difference was found in the plasma vitamin E content of the patients. Plasma malondialdehyde content was significantly higher /P less than 0.001/ in both sexes in the RA and OA groups as compared to the controls. Plasma catalase activity in both sexes was significantly higher (P less than 0.01) in RA and OA groups while RBC glutathione-peroxidase showed significantly (P less than 0.001) higher activity only in the female RA group, as compared to the control subjects. A difference was found between RA and OA groups in malondialdehyde content and in glutathione-peroxidase activity in subjects of both sexes.

Comparative investigations on vitamin A level of plasma in some rheumatic diseases.

The vitamin A levels in the plasma of patients suffering from rheumatoid arthritis, ankylosing spondylitis, spondylosis, ankylosing hyperostosis (whether or not connected with diabetes) were investigated. Somatically healthy neurotic patients and patients suffering from diabetes without rheumatological problems served as controls. It was found that the retinol level of plasma decreased in patients of both sexes suffering from rheumatoid arthritis and clinically active ankylosing spondylitis, but increased in female patients suffering from ankylosing hyperostosis connected with diabetes, and also in the diabetes group. The retinyl-esters content of plasma decreased in the rheumatoid arthritis group and increased in female patients suffering from spondylosis and in the clinically inactive ankylosing spondylitis group. The total vitamin A content changed only in the rheumatoid arthritis group where a lower level was found compared to a somatically healthy control group.

Effect of vitamin A treatment on immune reactivity and lipid peroxidation in patients with Sjögren's syndrome.

Patients with Sjögren's syndrome were treated with vitamin A (100,000 U) daily during a two-week period. The vitamin treatment significantly elevated their ADCC and NK activity. The lymphocyte blast transformation, however was not noticeably changed. After the treatment, the retinyl-ester and retinol level of the plasma significantly increased as did the plasma level of vitamin E. The level of TBA reactive substances (malondialdehyde) in the plasma increased, whilst the glutathione peroxidase and catalase activity of erythrocytes decreased. The activity of the plasma glutathione peroxidase increased, but not significantly.

Morphologic, endocrine and thermographic measurements of testicles in comparison with semen characteristics in mature Holstein-Friesian breeding bulls.

Twenty Holstein-Friesian breeding bulls (62-79 months of age) were examined 3 times, at 30-day intervals. Scrotal thermograms for assessment of scrotal surface temperature (SST) and blood samples for plasma testosterone concentrations were taken just before and then 45 and 90 min, respectively, after treatment with GnRH (50 micrograms, Gonavet, i.m. per bull). Following GnRH treatment, there generally were significant increases in mean values of both top SST (range, -0.1 to 1.4 degrees C) and bottom SST (range, 0.3 to 1.8 degrees C). Scrotal circumference was highly repeatable but SST and video-measurements of scrotal dimensions were less repeatable, because apparently they were affected by ambient temperature. Plasma testosterone concentrations before GnRH treatment were more repeatable than those after GnRH treatment. Correlations between examinations of 0.67 to 0.81 and -0.14 to 0.47, respectively, but the converse was true for SST measurements. Semen was collected with an artificial vagina 3 times per week for 12 weeks starting 2 weeks before the first examination. The total number of spermatozoa per ejaculate was highly repeatable and the percentage of motile and live spermatozoa were relatively consistent. Separate regressions for each variable and for each examination were conducted for these 3 semen characteristics as dependent variables. For the number of spermatozoa per ejaculate and for the percentage of motile spermatozoa, significant independent variables were plasma testosterone concentrations and difference between top and bottom SST, respectively. The slopes of these equations were nearly all negative and the R2 was from 0.15 to 0.42. For prediction of the percentage of live spermatozoa, both SST gradient and plasma testosterone concentrations were significant independent variables. For these regressions, the slopes were negative and the regression coefficients were generally lower than for the other 2 dependent variables (range, 0.16 to 0.25). Treatment with GnRH and assessment of SST and plasma testosterone concentrations have some correlation with the semen production in the mature bull.