A competitive marathon race decreases neutrophil functions in athletes

A full marathon is the longest running race in official track events and is a form of acute exercise. However, no studies have examined the acute neutrophil function response to a competitive marathon race. Thirty‐six male athletes who had just completed the 42.195 km course of the 50th Beppu‐Oita Mainichi Marathon were enrolled in this study. Neutrophil oxidative burst activity, phagocytic activity and expression of CD11b and CD16 per cell were measured by flow cytometry immediately before and after the marathon. Total leukocyte/neutrophil counts increased significantly (p < 0.001), whereas total oxidative burst activity per neutrophil cell decreased significantly after the race (p < 0.001). Furthermore, total phagocytic activity per neutrophil cell also decreased after the race, although it was not significant (p = 0.08). Although CD11b expression per cell did not change, the expression of CD16 per cell significantly decreased (p < 0.001) after the race. In conclusion, a competitive marathon race decreased neutrophil functions (oxidative burst activity and phagocytic activity), which may be partly due to a decrease in CD16 expression. The increase in total neutrophil counts might reflect a compensatory response to counteract the decrease in neutrophil functions. Copyright © 2003 John Wiley & Sons, Ltd.     

The antioxidant enzyme peroxiredoxin-2 is depleted in lymphocytes seven days after ultra-endurance exercise

Abstract

Purpose. Peroxiredoxin-2 (PRDX-2) is an antioxidant and chaperone-like protein critical for cell function. This study examined whether the levels of lymphocyte PRDX-2 are altered over 1 month following ultra-endurance exercise. Methods. Nine middle-aged men undertook a single-stage, multi-day 233 km (145 mile) ultra-endurance running race. Blood was collected immediately before (Pre), upon completion/retirement (Post), and following the race at Day 1, Day 7 and Day 28. Lymphocyte lysates were examined for PRDX-2 by reducing and non-reducing SDS-PAGE with western blotting. In a sub-group of men who completed the race (n = 4), PRDX-2 oligomeric state (indicative of redox status) was investigated. Results. Ultra-endurance exercise caused significant changes in lymphocyte PRDX-2 (F_(4,32) 3.409, p = 0.020, η² = 0.299): 7 days after the race, PRDX-2 levels in lymphocytes had fallen to 30% of pre-race values (p = 0.013) and returned to near-normal levels at Day 28. Non-reducing gels demonstrated that dimeric PRDX-2 (intracellular reduced PRDX-2 monomers) was increased in three of four race completers immediately post-race, indicative of an ‘antioxidant response’. Moreover, monomeric PRDX-2 was also increased immediately post-race in two of four race-completing subjects, indicative of oxidative damage, which was not detectable by Day 7. Conclusions. Lymphocyte PRDX-2 was decreased below normal levels 7 days after ultra-endurance exercise. Excessive accumulation of reactive oxygen species induced by ultra-endurance exercise may underlie depletion of lymphocyte PRDX-2 by triggering its turnover after oxidation. Low levels of lymphocyte PRDX-2 could influence cell function and might, in part, explain reports of dysregulated immunity following ultra-endurance exercise.     

Effect of black cumin (Nigella sativa) on cadmium-induced oxidative stress in the blood of rats

The protective effect of black cumin (Nigella sativa=NS) on cadmium-induced oxidative stress was studied in rats. The rats were randomly divided into three experimental groups: A (conrol), B (Cd treated), and C (Cd+NS treated), each containing 10 animals. The Cd-treated and Cd+NS-treated groups were injected subcutaneously daily with CdCl₂ dissolved in isotonic NaCl in the amount of 2 mL/kg for 30 d, resulting in a dosage of 0.49 mg Cd/kg/d. The control group was injected with only isotonic NaCl (2 mL/kg/d) throughout the experiment (for 30 d). Three days prior to induction of CdCl₂, the Cd+NS-treated group received a daily intraperitoneal injection of 0.2 mL/kg NS until the end of the study. Cd treatment increased significantly the malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also increased significantly the antioxidant levels (superoxide dismutase, glutathione peroxidase, and catalase) (p<0.05) compared to the control group. Cd+NS treatment decreased significantly the elevated malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also reduced significantly the enhanced antioxidant levels (p<0.05). Cd treatment increased significantly the activity of iron levels (p<0.05) in the plasma compared to the control group. Cd+NS treatment decreased the activity of iron levels (p<0.05) in the plasma compared to the Cd-treated group. In the control group with no treatment, histology of erythrocytes was normal. In the Cd-treated group, there were remarkable membrane destruction and hemolytic changes in erythrocytes. In the Cd+NS treated group, these changes were less than in the Cd-treated group. Our results show that N. sativa exerts a protective effect against cadmium toxicity.     

Protective Effects of Selenium and Vitamin E Combination on Experimental Colitis in Blood Plasma and Colon of Rats

Ulcerative colitis increases oxidative damage accompanied by production of free oxygen radicals. Selenium (Se) and vitamin E are two natural antioxidants. The present study was undertaken to investigate the possible protective role of Se and vitamin E combination in experimental colitis induced by acetic acid (AA) in rats. This study was carried out on three groups, namely the first (control), the second (experimental colitis group, 2 ml 5% acetic acid), and the third groups (2 ml 5% acetic acid, vitamin E (100 mg/kg body weight (bw)) plus Se (0.2 mg/kg bw)). The activities of catalase (CAT), prolidase (PRS), myeloperoxidase (MPO), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), total thiol (T-SH) were determined in plasma and colon samples. Macroscopic and microscopic damages in colon were increased by AA treatment (p < 0.01 and p < 0.01, respectively), whereas they were decreased by selenium and vitamin E treatment (p < 0.05 and p < 0.01, respectively). The activities of CAT and PRS in the plasma and colon were significantly affected (p < 0.05 and p < 0.01) by treatment of AA, Se, and vitamin E. MPO activity in colon was increased (p < 0.01) by AA treatment and decreased (p < 0.05) by Se and vitamin E administration. The values of TOS and OSI in plasma were increased (p < 0.5) by AA. The TAC and T-SH in colon were decreased (p < 0.05) by AA and increased (p < 0.05) by Se and vitamin E. Based upon these results, Se and vitamin E may play an important role in preventive indication of the oxidative damage associated by acetic acid caused inflammation.     

Visceral Adipose Tissue in Women: Longitudinal Study of the Effects of Fat Gain,Time, and Race

Objective: To determine the effects of fat gain, time, and race on the accumulation of visceral adipose tissue (VAT) in a group of normal‐weight premenopausal women. Research Methods and Procedures: Sixty‐five women participated in the study (32 African American and 33 white). The mean age of subjects was 34 ± 6 years (range, 22 to 47 years). Eligible subjects were women who had body mass indices <25 kg/m² at baseline and who had completed evaluations at baseline and at follow‐up year 1, without intervention. A subset of subjects was reevaluated annually for up to 4 years. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. A linear mixed model was used to examine changes in VAT over time, with total body fat as a covariate Results: Total fat mass was not significantly different between races at baseline and increased significantly in both groups over time (p < 0.001). Time‐related increases in total body fat were greater in African‐American women (p < 0.01). VAT was significantly higher in white women at baseline (p < 0.01) and increased significantly over time in both races (p < 0.01), but remained higher in white women (p < 0.001). Increases in VAT, relative to total body fat, were greater than the increases in total body fat over time, independent of age and race (p < 0.001). Discussion: Gaining total body‐fat mass results in a higher increase in VAT, relative to total body fat, regardless of race and age, although African‐American women maintain a lower VAT levels across time.     

Compromised antioxidant status and persistent oxidative stress in lung transplant recipients

Oxidative stress may be a key feature, and hence important determinant, of tissue injury and allograft rejection in lung transplant recipients. To investigate this, we determined the antioxidant status (urate, ascorbate, thiols and α-tocopherol) and lipid peroxidation status (malondialdehyde) in bronchoalveolar lavage (BAL) fluid and blood serum of 19 consecutive lung transplant recipients 2 weeks and 1, 2, 3, 6, and 12 months post-surgery. BAL fluid and blood samples from 23 control subjects and blood from 8 patients two days before transplantation were obtained for comparison. Before surgery, the antioxidant status of patients was poor as serum ascorbate and total thiol concentrations were significantly (p < 0.05) lower than control subjects. Two weeks post-surgery, ascorbate and total thiol concentrations were still low and urate concentrations had fallen compared to control subjects (p < 0.01). At this time, BAL fluid urate concentration was higher (p < 0.01), ascorbate concentration was lower (p < 0.01) and reduced glutathione concentrations were similar to control subjects. MDA, a product of lipid peroxidation, was higher (p < 0.01) in both BAL fluid and serum obtained from transplant patients compared to control subjects. During the first 12 months post-surgery, little improvement in antioxidant status or extent of lipid peroxidation was seen in transplant recipients. Regression analysis indicated no difference in serum or BAL fluid antioxidant status in patients with acute rejection compared to those without. In conclusion, lung transplant recipients have a compromised antioxidant status before surgery and it remains poor for at least the first year following the operation. In addition, these patients have elevated MDA concentrations in both their lung lining fluid and blood over most of this time. Oxidative stress is not, however, a sufficiently sensitive endpoint to predict tissue rejection in this group.     

Alterations in plasma essential trace elements selenium, manganese, zinc, copper, and iron concentrations and the possible role of these elements on oxidative status in patients with childhood asthma

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r=0.485, p<0.021), and a negative correlation between TAC and MDA values (r= −0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.     

Procyanidin B1 promotes in vitro maturation of pig oocytes by reducing oxidative stress

Oxidative stress negatively affects the in vitro maturation (IVM) of oocytes. Procyanidin B1 (PB1) is a natural polyphenolic compound that has antioxidant properties. In this study, we investigated the effect of PB1 supplementation during IVM of porcine oocytes. Treatment with 100 μM PB1 significantly increased the MII oocytes rate (p <0.05), the parthenogenetic (PA) blastocyst rate (p <0.01) and the total cell number in the PA blastocyst (p < 0.01) which were cultured in regular in vitro culture (IVC) medium. The PA blastocyst rate of regular MII oocytes activated and cultured in IVC medium supplemented with 100 and 150 μM PB1 significantly increased compared with control (p < 0.01 and p < 0.05). We also evaluated the reactive oxygen species (ROS) levels, mitochondrial membrane potential (Δψm) levels, glutathione (GSH) levels, and apoptotic levels in MII oocytes and cumulus cells following 100 μM PB1 treatment. The results showed that the PB1 supplementation decreased ROS production and apoptotic levels. In addition, PB1 was found to increase Δψm levels and GSH levels. In conclusion, PB1 inhibited apoptosis of oocytes and cumulus cells by reducing oxidative stress. Moreover, PB1 improved the quality of oocytes and promoted PA embryo development. Taken together, our results suggest that PB1 is a promising antioxidant additive for IVM of oocytes.     

Antioxidant status and lipid peroxidation in hemodialysis patients undergoing erythropoietin and erythropoietin-vitamin E combined therapy

In this study, plasma and red blood cell (RBC) antioxidant status and plasma lipid peroxidation were investigated in 46 hemodialysis patients. In addition, the effect of erythropoietin (EPO) and EPO-vitamin E combination therapy on plasma and RBC antioxidant status, and plasma lipid peroxidation were examined.

There were 10 healthy subjects in the control group and 10 hemodialysis patients in the untreated group. The third group included 36 hemodialysis patients that were given EPO (100 U/kg) for 3 months, 3 times per week. The fourth group included 36 hemodialysis-patients from the EPO group that were given EPO at a 50% decreased dose + vitamin E (300 mg/day) for 3 months.

MDA levels in the untreated group, the EPO group and the EPO + vitamin E groups were found to be higher than the control group (p<0.001, in both). Furthermore, MDA levels in both of the treatment groups were lower when compared to the untreated group (p<0.001, in both). Plasma vitamin E levels in the untreated, the EPO group and EPO + vitamin E groups were lower than the control group (p<0.001). In contrast, plasma vitamin E levels in the treatment groups were higher in comparison with the control group (p<0.05). SOD activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p<0.001). SOD activities in the treatment groups were higher than the control group (p<0.001). The SOD activities in the EPO + vitamin E group increased when compared to the EPO group (p<0.001). CAT activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p<0.001 in untreated and EPO groups, p<0.01 in EPO + vitamin E group). CAT activities in EPO and EPO + vitamin E groups were increased when compared to the untreated group (p<0.01).

In conclusion, our findings have shown that antioxidant status decreased and lipid peroxidation increased in hemodialysis patients. EPO has an antioxidant effect on the RBC and plasma antioxidant status, and plasma lipid peroxidation. These effects were moderately increased by the combination of vitamin E and EPO.     

Effect of phototherapy on oxidant/antioxidant status: a randomized controlled trial

In order to evaluate the effect of different types of phototherapy on oxidant/antioxidant status in hyperbilirubinemic neonates, an interventional randomized control trial was conducted on 120 neonates ≥35 weeks’ gestational age with indirect hyperbilirubinemia reaching phototherapy level. This study is registered with ClinicalTrials.gov as NCT03074292. Neonates were assigned to three groups; 40 neonates received conventional phototherapy, 40 received intensive phototherapy and 40 received blue light-emitting diodes (LED) phototherapy. Complete blood count (CBC), total serum bilirubin (TSB), total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), copper (Cu), zinc (Zn), and iron (Fe) levels were measured before and 24?hours after phototherapy. TSB decreased postphototherapy in all three groups (p < .05 for all), with significantly lower levels following intensive and LED phototherapy compared to conventional phototherapy (p < .05 for both). TAC decreased postphototherapy in the three groups (p < .05 for all). MDA and NO increased postphototherapy (p < .05 for all), with the intensive phototherapy group having the highest levels followed by the conventional while LED phototherapy group showed the lowest levels in comparison to the other groups (p < .05). Cu, Zn and Fe increased postphototherapy in all three groups (p < .05 for all). Positive correlations were found between postphototherapy TSB with TAC, Cu and Zn (p < .05) and negative correlations with MDA, NO and Fe (p < .05) among neonates of the 3 studied groups. In conclusion, different photo therapies have an impact on oxidant/antioxidant balance and are associated with increased oxidative stress markers with the LED phototherapy being the safest.     

Comparison of the effects of melatonin and pentoxifylline on carbon tetrachloride-induced liver toxicity in mice

The purpose of the study was to determine whether along and in combination melatonin (MLT) and pentoxlfylline (PTX) exerted beneficial effects on histopathological changes and changes in oxidant and antioxidant systems in liver caused by CCl₄-induced liver toxicity in mice. Mice were randomly divided into six groups: control, olive oil, toxicity, MLT, PTX, PTX+MLT. MLT 10 mg/kg/day, PTX 50 mg/kg/day, and the same individual doses in MLT+PTX combination were given intraperitoneally to mice for 7 day. CCl₄ 0.8 mg/kg/day was administered on the 4th, 5th, and 6th days of therapy in all groups except the control and olive oil groups. In the toxicity group, increased concentrations of malondialdehyde (MDA) and lipid hydroperoxides (LOOH) and decreased glutathione peroxidase (GSH-Px) and catalase (CAT) activities were found compared to the control and olive oil groups (p < 0.05). Compared to the toxicity group, both the PTX group and the PTX+MLT group had decreased MDA and LOOH levels, whereas MLT reduced only LOOH levels (p < 0.01). MLT, PTX and MLT+PTX increased the GSH-Px and CAT activities compared to the toxicity group (p < 0.05). MLT increased CAT activity compared to PTX and MLT+PTX (p < 0.05). Superoxide dismutase enzyme activity did not change in any group (p < 0.05). Histopatholically, ballooning, degeneration, apoptosis, and bridging necrosis were seen in the toxicity group. MLT, PTX and MLT+PTX decreased the apoptosis and bridging necrosis (p < 0.01), and PTX and MLT+PTX decreased balloon degeneration compared to the toxicity group (p < 0.01). These results indicate that administration of PTX and MLT alone and in combination before onset of liver toxicity might prevent the oxidative damage by reducing oxidative stress and increasing antioxidant enzyme levels.     

Protective effects of antioxidants against UVA-induced DNA damage in human skin fibroblasts in culture

Ultraviolet A radiation (UVA, 320–400 nm) is mutagenic and induces genomic damage to skin cells. N-acetyl-cysteine (NAC), selenium and zinc have been shown to have antioxidant properties and to exhibit protective effects against UVA cytotoxicity. The present work attempts to delineate the effect of these compounds on genomic integrity of human skin fibroblasts exposed to UVA radiation using the single cell gel electrophoresis (SCGE) or Comet assay. The cells were incubated with NAC (5 mM), sodium selenite (0.6 μM) or zinc chloride (100 μM). Then cells were embedded in low melting point agarose, and immediately submitted to UVA fluences ranging from 1 to 6J/cm². In the Comet assay, the tail moment increased by 45% (1J/cm²) to 89% (6J/cm²) in non-supplemented cells (p<0.01). DNA damage was significantly prevented by NAC, Se and Zn, with a similar efficiency from 1 to 4J/cm² (p<0.05). For the highest UVA dose (6J/cm²), Se and Zn were more effective than NAC (p<0.01).     

Comparison of Different Forms of Dietary Selenium Supplementation on Growth Performance,Meat Quality,Selenium Deposition,and Antioxidant Property in Broilers

This study was conducted to investigate the effects of different sources of dietary selenium (Se) supplementation on growth performance, meat quality, Se deposition, and antioxidant property in broilers. A total of 600 one-day-old Ross 308 broilers with an average body weight (BW) of 44.30 ± 0.49 g were randomly allotted to three treatments, each of which included five replicates of 40 birds. These three groups received the same basal diet containing 0.04 mg Se/kg, supplemented with 0.15 mg Se/kg from sodium selenite (SS) or from l-selenomethionine (l-Se-methionine (Met)) or from d-selenomethionine (d-Se-Met). The experiment lasted 42 days. Both Se source and time significantly influenced (p < 0.01) drip loss of breast muscle. Supplementation with l-Se-Met and d-Se-Met were more effective (p < 0.05) in decreasing drip loss than SS. Besides, the pH value of breast muscle was also significantly influenced (p < 0.05) by time. The SS-supplemented diet increased more (p < 0.05) liver, kidney, and pancreas glutathione peroxidase (GSH-Px) activities than the d-Se-Met-supplemented diet. In addition, l-Se-Met increased more (p < 0.01) liver and pancreas GSH-Px activities than d-Se-Met. The antioxidant status was greatly improved in broilers of l-Se-Met-treated group in comparison with the SS-treated group and was illuminated by the increased glutathione (GSH) concentration in serum, liver, and breast muscle (p < 0.05); superoxide dismutase (SOD) activity in liver (p < 0.01); total antioxidant capability (T-AOC) in kidney, pancreas, and breast muscle (p < 0.05) and decreased malondialdehyde (MDA) concentration in kidney and breast muscle (p < 0.05) of broilers. Besides, supplementation with d-Se-Met was more effective (p < 0.01) in increasing serum GSH concentration and decreasing breast muscle MDA concentration than SS. l-Selenomethionine supplementation significantly increased GSH concentration in liver and breast muscle (p < 0.05); SOD activity in liver (p < 0.01); and T-AOC in liver, pancreas, and breast muscle (p < 0.05) of broilers, compared with broilers fed d-Se-Met diet. The addition of l-Se-Met and d-Se-Met increased (p < 0.01) Se concentration in serum and different organs studied of broilers in comparision with broilers fed SS diet. Therefore, dietary l-Se-Met and d-Se-Met supplementation could improve antioxidant capability and Se deposition in serum and tissues and reduce drip loss of breast muscle in broilers compared with SS. Besides, l-Se-Met is more effective than d-Se-Met in improving antioxidant status in broilers.     

Impact of radiofrequency radiation on DNA damage and antioxidants in peripheral blood lymphocytes of humans residing in the vicinity of mobile phone base stations

Radiofrequency radiations (RFRs) emitted by mobile phone base stations have raised concerns on its adverse impact on humans residing in the vicinity of mobile phone base stations. Therefore, the present study was envisaged to evaluate the effect of RFR on the DNA damage and antioxidant status in cultured human peripheral blood lymphocytes (HPBLs) of individuals residing in the vicinity of mobile phone base stations and comparing it with healthy controls. The study groups matched for various demographic data including age, gender, dietary pattern, smoking habit, alcohol consumption, duration of mobile phone use and average daily mobile phone use. The RF power density of the exposed individuals was significantly higher (p < 0.0001) when compared to the control group. The HPBLs were cultured and the DNA damage was assessed by cytokinesis blocked micronucleus (MN) assay in the binucleate lymphocytes. The analyses of data from the exposed group (n = 40), residing within a perimeter of 80 m of mobile base stations, showed significantly (p < 0.0001) higher frequency of micronuclei when compared to the control group, residing 300 m away from the mobile base station/s. The analysis of various antioxidants in the plasma of exposed individuals revealed a significant attrition in glutathione (GSH) concentration (p < 0.01), activities of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.001) and rise in lipid peroxidation (LOO) when compared to controls. Multiple linear regression analyses revealed a significant association among reduced GSH concentration (p < 0.05), CAT (p < 0.001) and SOD (p < 0.001) activities and elevated MN frequency (p < 0.001) and LOO (p < 0.001) with increasing RF power density.     

Partial replacement of dietary buffalo meat on the bone with chicken carcass improves serum antioxidant profile of zoo‐housed Indian leopards (Panthera pardus fusca)

This experiment was conducted to study the effect of gradual replacement of dietary buffalo meat on the bone (BMB) with chicken carcass (CC) on nutrient utilization, serum cortisol, and total serum antioxidant profile of zoo‐housed Indian leopard. Twelve adult leopards were randomly distributed into a replicated Latin square design comprising three treatments, three periods, four animals, and three sequences. Leopards in group T₁ were fed normal zoo diet of BMB. On the basis of dry matter, 10% and 20% of BMB was replaced with CC in groups T₂ and T₃, respectively. Each experimental period comprised 21 days. During each period, a digestion trial of 4‐day collection period was conducted after an adaptation period of 17 days. On Day 21 of each experimental period, blood was collected from all the animals by puncturing the ventral coccygial vein. Intake and apparent digestibility of major nutrients were similar among the groups. Replacement of 20% BMB with addition of CC increased (p < 0.001) the calculated supply of I, niacin, and vitamin A. Carotenoid intake increased (p < 0.01) with increased level of CC in the diet. Serum concentration of cortisol decreased (p < 0.01) whereas serum concentration of total carotenoids increased (p < 0.001) with increased level of CC in the diet. Serum concentration of antioxidant enzymes increased (p < 0.001) with increased level of CC in the diet. It was concluded that replacement of 20% of BMB with CC increased antioxidant profile. This may reduce oxidative stress in zoo‐housed Indian leopards without any adverse effect on nutrient utilization.     

Zinc deficiency decreases plasma erythropoietin concentration in rats

In 1985, Paterson and Bettger found hypoplastic hematopoiesis in severely zinc-deficient rats. Therefore, we investigated plasma erythropoietin concentration in zinc-deficient rats. Forty 4-wk-old male Sprague-Dawley rats were assigned into 4 dietary treatment groups of 10 for the 4-wk study: zinc-deficient group (4.5 mg zinc and 35 mg iron/kg; −Zn), iron-deficient group (30 mg zinc/kg, no supplemental iron; −Fe), zinc/iron-deficient group (4.5 mg zinc/kg, no supplemental iron; −Zn−Fe), and control group (AIN-93G; Cont). Water intake determined at d 19 was similar among all treatment groups. At d 27–28, bioimpedance was measured. The intracellular water/extracellular water ratio was significantly increased in the −Zn group (p<0.05). Compared to the Cont, group, the plasma erythropoietin concentration was increased by iron deficiency and decreased by zinc deficiency (p<0.01). Hematocrit was significantly decreased in both the −Fe and −Zn−Fe groups and was significantly increased in the −Zn group (p<0.01). Transferrin saturation in the −Fe and −Zn−Fe groups was significantly lower than the Cont group (p<0.01), and that of the −Zn group was highest among all groups. The low plasma erythropoietin concentration might account for depressed hematopoiesis associated with zinc deficiency.     

Selenomethionine: an Effective Selenium Source for Sow to Improve Se Distribution,Antioxidant Status,and Growth Performance of Pig Offspring

The present study was to investigate the efficiency of maternal selenomethionine intake on growth performance, Se distribution, and antioxidant status of pig offspring by comparing with sodium selenite. A total of 12 sows (Landrace × Yorkshire) with same pregnancy were randomly divided into two groups; each group was replicated six times. These two groups received the same basal gestation and lactation diets containing 0.04 mg Se/kg, supplemented with 0.3 mg Se/kg sodium selenite and selenomethionine (i.e., seneno-dl-methylseleno), respectively. The feeding trial lasted for 60 days, with 32 and 28 days for gestation and lactation period, respectively. Compared with sodium selenite, maternal selenomethionine intake significantly (p < 0.05) increased the daily weight gain of piglet from birth to weaning. The Se concentration in the colostrum and milk and tissue Se content of piglets were significantly higher (p < 0.05) in the selenomethionine-treated group. The antioxidant status was greatly improved in piglets of selenomethionine-treated group and was illuminated by the increased total antioxidant capability, glutathione peroxidase, superoxide dismutase, and glutathione, and decreased the malondialdehyde level in the organs of piglets. The increased (p < 0.05) triiodothyronine (T₃) and decreased (p < 0.05) thyroxine (T₄) concentration indicated the improved protein synthesis and energy production in the selenomethionine-treated group. The increased (p < 0.05) pancreatic digestive enzymes of protease, amylase, and lipase activities indicated that maternal selenomethionine intake may have a positive effect on the degradation and absorption of nutrients in its piglets. In summary, we concluded that maternal selenomethionine intake increased Se deposition, antioxidant status, and nutrient use efficiency, thus providing an effective way to improve the growth performance of piglets from birth to weaning.     

Orally administered tryptophan and experimental type 2 diabetes

There is a link between diabetes and oxidative stress. Hyperglycaemia leads to free radical generation and alterations of endogenous antioxidants. Our aim is to study the effect of orally administered L-tryptophan (TRP), the melatonin precursor, an endogenous antioxidant, on circulating levels of glycaemia, insulin and melatonin, and on the superoxide dismutase and catalase antioxidant systems in non-diabetic (ND) and type 2 diabetic (n5-STZ) male Wistar rats.At 19:30 every day for 15 days, TRP (125 mg/kg body weight) was administered orally. At 09:00 every two days the glycaemia was measured and every day the intake of food and water was recorded. At the beginning and end of treatment (at 09:00; 21:00; 02:00) plasma insulin and melatonin levels were measured, and (at 09:00) the enzymatic activities of catalase and superoxide dismutase (SOD) in erythrocytes were also measured. Glycaemia values were greater (p < 0.01) in n5-STZ rats than in ND rats, while insulin levels were lower (p < 0.05) at all times studied and these parameters were not altered by the TRP administration. Melatonin levels at 02:00 were lower in n5-STZ than in ND rats (p < 0.05). The TRP administration did not modify the circulating melatonin levels in ND rats, but raised (p < 0.01) the levels at 02:00 in the treated n5-STZ group. In ND rats after TRP administration there was a decline in catalase activity (p < 0.05), while in n5-STZ rats there was a rise (p < 0.01) at the end of treatment. However, there were no significant changes in SOD activity. There was increased food intake (g/day) in the treated n5-STZ group (p < 0.01). In conclusion, the oral administration of TRP did not modify glycaemia or insulinaemia levels, but raised melatonin levels in diabetic rats at 02:00, lowered catalase activity in ND rats but raised it in n5-STZ rats, and increased food intake in n5-STZ rats. (Mol Cell Biochem 261: 57–61, 2004)     

Protective role of erdosteine on vancomycin-induced oxidative stress in rat liver

Drug-induced liver toxicity is a common cause of liver injury. This study was designed to elucidate whether high dose vancomycin (VCM) induces oxidative stress in liver and to investigate the protective effects of erdosteine, an expectorant agent. Twenty-two young Wistar rats were divided into three groups as follows: control group, VCM, and VCM plus erdosteine. VCM was administered intraperitoneally in the dosage of 200 mg/kg twice daily for 7 days. Erdosteine was administered orally administered once a day at a dose of 10 mg/kg body weight. The activities of antioxidant enzymes such as superoxide dismutase and catalase as well as the concentration of malondialdehyde, as an indicator of lipid peroxidation, were measured to evaluate oxidative stress in homogenates of the liver. VCM administration increased malondialdehyde levels (p < 0.001), superoxide dismutase (p < 0.01) and catalase (p < 0.001) activities. Erdosteine co-administration with VCM injections caused significantly decreased malondialdehyde levels (p < 0.001), superoxide dismutase (p < 0.01) and catalase (p < 0.001) activities in liver tissue when compared with VCM alone. It can be concluded that erdosteine may prevent VCM-induced oxidative changes in liver by reducing reactive oxygen species.     

Incidence of exercise-associated hyponatremia during a high-altitude 161-km ultramarathon

[Purpose]Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161-km race held at a high altitude (2,800 m-3,840 m).[Methods]Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na⁺]) level.[Results]Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30-hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na⁺] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na⁺] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na⁺] levels were associated with higher serum creatine kinase values (R²=0.1, p<0.005).[Conclusion]High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.